Paszek has won three singles titles on the WTA tour, as well as three singles and three doubles titles on the ITF circuit in her career. On 11 February 2013, she reached her best singles ranking of world number 26. On 6 May 2013, she peaked at world number 93 in the doubles rankings.
Paszek was introduced to tennis by her mother, Françoise Paszek, at age four-and-a-half. Her mother is a Chilean-born Austrian of Polish and French descent; and her father, Ariff Mohamed, a Tanzanian-born, Kenyan-raised Canadian of Indian descent. Tamira has a Polish surname from her maternal grandfather.
As a junior, Paszek was a finalist in the 2005 Girls' Singles Championship at Wimbledon and at the US Open – Girls' Singles in 2006.
In September 2005 she won her first title at an ITF tournament in Sofia. In October of the same year she received a wild card to appear at her first WTA tournament in Linz; she defeated Elena Vesnina in the first round and lost to Ana Ivanovic after a tough first set.
In 2006, she passed qualifications in Istanbul, where she lost in the second round to Catalina Castaño; and in Portorož at the Banka Koper Slovenia Open, where she won her first WTA title by defeating number 6 seed Maria Elena Camerin in straight sets. This was a career-first tour singles title in only her third tour main draw. That title made her the youngest tour singles titlist in 2006 and the seventh-youngest of all-time, the youngest winner being Tracy Austin. A month later, at the Zürich Open, she lost to Camerin in the second round of qualifying. She finished 2006 as world number 181 in the WTA rankings.
Paszek started the 2007 WTA Tour at the Australian Open, where she qualified for the main draw and defeated top-40 player Séverine Brémond in straight sets in the first round, before losing to number 22 seed Vera Zvonareva.
After her loss to Li Na in the second round of the Miami Masters, Paszek broke into the top 100 of the WTA rankings. At the 2007 French Open she was defeated by Justine Henin in the second round.
At Paszek's first grass tournament of her career, she reached the third round in Birmingham, losing to Maria Sharapova in a tight match. At the 2007 Wimbledon Championships she reached the fourth round after beating two seeded players, number 17 seed Tatiana Golovin and number 12 seed Elena Dementieva; she then eventually lost to number 5 seed Svetlana Kuznetsova in straight sets. The win pushed her up 19 places from number 54 to number 35, a career high and only a few spots from a guaranteed seeding at the US Open.
Paszek also participated at the Fed Cup for Austria in 2007. She won her first two matches in the group stage against Australia but lost both her matches in the World Group play-offs against Israel; a singles match against Shahar Pe'er and a doubles match, partnering Melanie Klaffner.
Paszek debuted on the 2007 US Open, reaching the fourth round, beating the number 24 and number 11 seeds, Francesca Schiavone and Patty Schnyder, on the way. She lost to the sixth seed, Anna Chakvetadze.
Paszek decided against defending her title in the Banka Koper Slovenia Open in Portorož, Slovenia, in favour of the larger China Open tournament in Beijing. However, she lost in the second round to fourth-seeded Elena Dementieva (whom she beat in Wimbledon) in less than an hour.
At the 2008 ASB Classic in Auckland, New Zealand, Paszek made it to the semifinals, losing to veteran Lindsay Davenport. In the first round of the 2008 Australian Open, Paszek played third-seeded Jelena Janković of Serbia. Paszek easily won the first and Janković went on to win the second set. In the deciding set, Paszek led by two games and had three match points before Janković came back to win the three-hour match.
Following this she lost in the first round of Doha to Patty Schnyder. Then she competed for the first time as a seed in a tier 1 tournament at Indian Wells retiring in the third round to Casey Dellacqua. Then in Miami she was defeated by Anna Chakvetadze in the second round.
This started a losing streak of six straight matches running through the French Open and Wimbledon. At Wimbledon she lost her second marathon match of the year to Francesca Schiavone. It came to an end in Los Angeles where she defeated Aiko Nakamura only to lose to Flavia Pennetta in the second round.
On 31 July, Paszek beat world number one Ana Ivanovic in the third round of the Rogers Cup in Montreal in three sets. In the quarterfinals, she played Victoria Azarenka, to whom she lost. Then she lost in the first round of Cincinnati to Petra Cetkovská. At the US Open Paszek defeated the 23rd seed Maria Kirilenko, only then to lose to the lower ranked opponent Magdaléna Rybáriková.
Paszek was runner up in Bali. She reached the final after taking out the 7th seed Flavia Pennetta and the top seed Daniela Hantuchová. She lost the final against Patty Schnyder. She then withdrew from the Generali Ladies Linz due to injury.
Paszek ended her professional relationship with coach Lari Passos and is now coached by Angel Giminez.
Paszek lost in the first round of the Australian Open to Australian wild card Jelena Dokić in three sets.
Paszek passed the first round at Indian Wells, winning in straight sets against Mara Santangelo, and lost in the second round against 21st seed Alisa Kleybanova.
In January, Paszek lost in second round of qualifying in Auckland. After defeating Carly Gullickson she retired in her match against Rebecca Marino. Her next tournament was the 2010 Moorilla Hobart International. She scored a big win after defeating Roberta Vinci, but then lost to Gisela Dulko in a long three-setter.
Her next tournament was the 2010 Australian Open where she lost to Julia Görges in the first round. At the tournament in Paris, Paszek lost to eventual runner-up Lucie Šafářová. To reach the main draw at 2010 Dubai Tennis Championships, Paszek entered qualifying. She defeated Tsvetana Pironkova in first round, but then lost to Anna-Lena Grönefeld. After Dubai she entered at Indian Wells, but lost to Julie Coin. At the 2010 Sony Ericsson Open, Paszek defeated Anne Keothavong, but then lost to 22nd seed Anastasia Pavlyuchenkova.
Paszek lost in early rounds of Marbella, Barcelona and Fes, and didn't enter the 2010 French Open. Instead, Paszek played the $25,000 ITF tournament in Izmir. She won that tournament, beating Çağla Büyükakçay. Her next tournament was ITF Budapest. She qualified, defeating Vanda Lukács and Jana Čepelová, and reached the second round, losing to Lenka Wienerová.
She then entered the 2010 Wimbledon Championships, qualified, but lost to Kurumi Nara in the second round.
She tried to qualify in Budapest defeating Eleni Daniilidou and Jessica Moore but lost to Andreja Klepač. Her next tournament was the 2010 ECM Prague Open where she entered qualifying. Paszek defeated Tadeja Majerič and then crushed first seed Anastasia Rodionova. She then lost to Liana Ungur. After losing the first set 6–2, Paszek went to play better, breaking Ungur serve and lead 2–0. On the other side Ungur came back broke twice to lead 3–2. Paszek then retired because of the heat and a stomach complaint. But, because Gisela Dulko withdrew, Paszek gained her chance to enter to the main draw. She faced Frenchwoman Alizé Cornet and lost in a match that lasted three hours and 40 minutes.
Paszek's next tournament was the 2010 Banka Koper Slovenia Open, where she defeated Jelena Kostanić Tošić for her first main draw win since Ponte Vedra Beach in 2009. She then faced Stefanie Vögele and lost.
After some bad losses in qualifying of the Premier tournaments, Paszek found her form in the 2010 US Open where she entered qualifying. She defeated Michaëlla Krajicek, Korea's Kim So-jing and Russia's Evgeniya Rodina to reach the main draw. In the final qualifying round, Paszek trailed Rodina 2–6 after the first set before coming back to win the second and blank the Russian in the third. In the first round of the main draw, she defeated 26th seed Lucie Šafářová, despite being three games behind in the second set. She lost to Chan Yung-jan in the second round.
Her next tournament was at the 2010 Bell Challenge. She defeated Marina Erakovic in the first and Jill Craybas in the second round. In her first quarterfinal of 2010 she defeated number 8 seed Sofia Arvidsson. She then crushed Christina McHale in the semifinal to book her place in the final, where she won the title by beating Bethanie Mattek-Sands.
Paszek started 2011 ranked number 89 and lost in the first round of Auckland to Sofia Arvidsson. She qualified for Hobart and reached the second round of the main draw before falling to Jarmila Gajdošová. Prior to the 2011 Wimbledon Championships, Paszek had a standard year before she went on to reach the quarterfinals of Wimbledon for the first time in her career, defeating world number seven and sixth seed Francesca Schiavone (her first top 10 win of 2011) in an epic third round match that lasted three hours and 42 minutes. Paszek finally prevailed, hitting a total of 40 winners to 36 unforced errors. Paszek played Russian Ksenia Pervak in the fourth round. She went on winning, beating Pervak in three sets, reaching the quarterfinals of a Grand Slam for the first time. She played number four seed Victoria Azarenka in the quarterfinals. The match started on Court 1 but was moved to Centre Court after the first game due to rain. Paszek lost, however, in straight sets.
Paszek began the year at the 2012 Brisbane International. In the 1st round, she lost to World Number 22 Ana Ivanovic 6-3, 6-3. Seeded 5th for qualifying at the 2012 Apia International Sydney, Paszek lost in the 1st round of qualifying to Bojana Jovanovski 6-0, 7-6(7). At the 2012 Australian Open, Paszek lost in the 1st round to 12th seed Serena Williams 6-3, 6-2.
At the 2012 Qatar Total Open, Paszek lost in the 1st round to qualifier Anne Keothavong 7-6(4), 7-6(5). Seeded 8th in qualifying at the 2012 Dubai Tennis Championships, Paszek lost in the 1st round of qualifying to Anastasia Rodionova 6-4, 6-4. Ranked 49 at the 2012 BNP Paribas Open, Paszek recorded her 1st win of the season by defeating World Number 65 Anastasiya Yakimova in the 1st round 6-4, 2-6, 6-1. In the 2nd round, Paszek faced 23rd seed Lucie Šafářová. Paszek retired trailing 6-3, 3-1 due to a right wrist injury. At the 2012 Sony Ericsson Open, Paszek was up against World Number 77 Anna Tatishvili in the 1st round. Paszek was forced to retire trailing 6-4, 4-3 due to a back injury.
Paszek began her clay court season at the 2012 Estoril Open. In the 1st round, she lost easily to 9th seed Polona Hercog 6-0, 6-3. At the 2012 Mutua Madrid Open, Paszek lost in the 1st round to Spanish wildcard Sílvia Soler Espinosa 6-7(2), 6-2, 6-2. Seeded 8th at the 2012 Internationaux de Strasbourg, Paszek had her 2nd win of the season by defeating World Number 103 Alberta Brianti in the 1st round 6-4, 0-6, 6-4. In the 2nd round, she lost to World Number 81 Johanna Larsson 6-2, 6-0. At the 2012 French Open, Paszek lost in the 1st round to 28th seed Peng Shuai 6-4, 6-3.
Paszek began her grass court season at the 2012 Aegon Trophy. As the top seed, Paszek was upset in the 1st round by World Number 137 Alison Riske 7-5, 6-4. Seeded 12th at the 2012 Aegon Classic, Paszek was defeated in the 1st round by World Number 76 Anne Keothavong 6-2, 7-5. Paszek´s final grass court warm up tournament before Wimbledon was the 2012 Aegon International. In the 1st round, she beat World Number 45 Marina Erakovic 7-5, 6-1. In the 2nd round, Paszek upset 8th seed Daniela Hantuchová 6-4, 3-6, 6-1. In the quarterfinals, she defeated World Number 40 Tsvetana Pironkova 6-0, 6-4. In the semifinals, Paszek upset 4th seed and defending champion Marion Bartoli 4-6, 7-5, 6-4 to reach her 1st WTA final since 2010. In the final, Paszek upset 5th seed Angelique Kerber 5-7, 6-3, 7-5 to win her 3rd WTA Title. Paszek was 5-3 down in the final set and saved five championship points. At the 2012 Wimbledon Championships, Paszek upset former World Number 1 and 7th seed Caroline Wozniacki in the 1st round 5-7, 7-6(4), 6-4. This match lasted 3 hours and 12 minutes. In the 2nd round, she beat World Number 60 Alizé Cornet 6-2, 6-1. In the 3rd round, she defeated World Number 36 Yanina Wickmayer 2-6, 7-6(4), 7-5. In the 4th round, she defeated 21st seed Roberta Vinci 6-2, 6-2 to reach the quarterfinals for the 2nd year in a row. In the quarterfinals, Paszek lost for the 2nd successive year to 2nd seed Victoria Azarenka 6-3, 7-6(4).
Representing Austria in the 2012 Summer Olympics, Paszek lost in the 1st round to Alizé Cornet 7-6(4), 6-4.
Paszek began her US Open series at the 2012 Rogers Cup. In the first round, she defeated World Number 25 Julia Görges 6-2, 6-1. In the 2nd round, Paszek faced World Number 1 Victoria Azarenka. Azarenka retired at 3-3 in the first set due to a left knee injury. In the 3rd round, Paszek easily defeated World Number 44 Carla Suárez Navarro 6-3, 6-0. In the quarterfinals, Paszek lost to 5th seed and eventual champion Petra Kvitová 6-3, 6-2. At the 2012 Western & Southern Open, Paszek was up against World Number 60 Sofia Arvidsson. Arvidsson won the 1st set 6-1. In the 2nd set, Arvidsson was leading 2-1 before Paszek retired because of a migraine. Her last tournament before the US Open was the 2012 New Haven Open at Yale. She lost in the 1st round to World Number 46 Sloane Stephens 6-3, 6-1. At the 2012 US Open, Paszek lost in the 1st round to World Number 67 Olga Govortsova 6-3, 6-4.
After the US Open, Paszek played at the 2012 Korea Open. In the 1st round, she beat World Number 45 Carla Suárez Navarro 7-6(8), 6-3. In the 2nd round, she defeated Korean wildcard So-ra Lee 6-2, 6-0. In the quarterfinals, Paszek lost to 6th seed Varvara Lepchenko 4-6, 7-6(3), 6-4. At the 2012 Toray Pan Pacific Open, she defeated qualifier Camila Giorgi in the 1st round 6-4, 6-3. In the 2nd round, Paszek lost easily to World Number 1 Victoria Azarenka 6-1, 6-1. At the 2012 China Open, Paszek got revenge on Olga Govortsova and defeated her in the 1st round 7-5, 0-6, 7-6(6). In the 2nd round, she lost to qualifier Elena Vesnina 7-6(5), 6-2. Seeded 7th at the 2012 Generali Ladies Linz, Paszek was defeated in the 1st round by qualifier Bethanie Mattek-Sands 6-2, 6-4. Her final tournament of the year was the 2012 BGL Luxembourg Open. Seeded 7th, she lost in the 1st round to World Number 47 Lucie Hradecká 6-3, 7-6(8).
Paszek ended the year ranked 30. This is her best season to date.
Paszek began the year at the 2013 Brisbane International. In the 1st round, she lost to World Number 31 Urszula Radwańska 2-6, 6-0, 6-2. After Brisbane, Paszek competed at the 2013 Apia International Sydney. She lost in the 1st round to World Number 22 Jelena Janković 6-2, 7-6(5). At the 2013 Australian Open, Paszek was the 30th seed. She achieved her first Australian Open victory since 2007 with an emphatic win over World Number 89 Stefanie Vögele in the 1st round 4-6, 6-4, 7-5. However, in the 2nd round, she was outplayed by American wildcard Madison Keys and lost 6-2, 6-1.
After the Australian Open, Paszek played at the 2013 Open GDF Suez. In the 1st round, she lost to Lucky Loser and eventual semifinalist Kiki Bertens 6-4, 7-5. At the 2013 Qatar Total Open, Paszek had another 1st round exit, losing to 13th seed Ana Ivanovic 6-1, 6-2. Seeded 23rd at the 2013 BNP Paribas Open, Paszek received a bye into the 2nd round. In the 2nd round, sh lost to American qualifier Mallory Burdette 7-6(0), 6-1. Seeded 26th at the 2013 Sony Open Tennis, Paszek again received a bye into the 2nd round. In the 2nd round, Paszek lost to World Number 57 Simona Halep 6-1, 6-7(4), 7-5.
Paszek's clay-court season began in Charleston at the 2013 Family Circle Cup. In the 1st round, she faced American qualifier Grace Min. Paszek retired after losing the 1st set 6-3 due to a left neck injury. After Charleston, she traveled to Europe to play in the 2013 Portugal Open. She lost in the 1st round to World Number 49 Monica Niculescu 6-1, 6-3. Seeded 2nd at the 2013 Internationaux de Strasbourg, Paszek lost in the 1st round to French wildcard Virginie Razzano 6-1, 6-4. Seeded 28th at the 2013 French Open, Paszek lost in the 1st round to World Number 78 Melanie Oudin 6-4, 6-3.
Paszek elected to contest at the 2013 Aegon Trophy in Nottingham. She opened her grass-court season with a hard-fought win over wildcard Anne Keothavong in the first round 7-6(6), 6-3. However, she would progress no further as she was forced to retire against Alison Riske at 4-6, 7-5, 2-0 in their second-round encounter due to a hamstring injury. At the 2013 AEGON Classic, she was seeded 4th and was given a first-round bye. She drew Riske again in the 2nd round and lost 2-6, 6-2, 6-3. Paszek entered the 2013 Aegon International as the defending champion, but again went out at the first hurdle, losing to Caroline Wozniacki after having to retire at 6-2, 2-2 due to a thigh injury. Her final grass-court event was the 2013 Wimbledon Championships, where she was seeded 28th. She lost in the first round to World Number 87 Alexandra Cadanțu 6-2, 7-5. As a result, Paszek dropped out of the Top 100.
Paszek took a two-week break following Wimbledon, making her next appearance on the hard-courts at the 2013 Bank of the West Classic in Stanford. In the 1st round, she faced qualifier Alla Kudryavtseva. Paszek recorded her 3rd win of the season when Kudryavtseva retired at 6-1, 6-7(4), 3-0 due to a heat illness. She lost in the 2nd round to 6th seed Varvara Lepchenko 6-4, 6-4. Her next tournament was the 2013 Southern California Open. In the 1st round, she suffered a 6-0, 6-0 thrashing at the hands of World Number 45 Daniela Hantuchová. She then played qualifying at the 2013 Rogers Cup. Seeded 24th for qualifying, she lost a marathon match in the 1st round of qualifying to Anastasia Rodionova 7-6(5), 5-7, 7-6(2). For the last Grand Slam tournament of the year, Paszek played qualifying at the 2013 US Open. In the 1st round of qualifying, she defeated Anna-Lena Friedsam 6-2, 6-2. Paszek lost in the 2nd round of qualifying to 3rd seed Andrea Hlaváčková 6-2, 2-6, 6-2.
After the US Open, she entered the 2013 Challenge Bell in Quebec City. She lost in the 1st round to World Number 84 Christina McHale. She then played two ITF Circuit events in the United States. The first tournament was the 2013 Coleman Vision Tennis Championships. In the 1st round, she defeated Olivia Rogowska. In the 2nd round, she lost to Anna Tatishvili 7-5, 6-2. At the 2013 Party Rock Open, Paszek defeated Adriana Pérez in the 1st round 7-6(8), 7-6(7). In the 2nd round, she lost to 6th seed, eventual finalist, and doubles partner Coco Vandeweghe 6-4, 6-2. However, she did capture the doubles title with Coco Vandeweghe marking her first tournament win in either singles or doubles in 2013. Her most impressive result of the year came in France at the 2013 Open GDF Suez Région Limousin, a $50,000 ITF tournament. Unseeded, Paszek upset 4th seed Johanna Konta in the 1st round 6-4, 6-4. In the 2nd round, she defeated Andreea Mitu 1-6, 6-3, 7-6(9). In the quarterfinals, she beat Nina Zander 6-2, 6-2. In the semifinals, she upset 1st seed Silvia Soler Espinosa 6-1, 6-0 for a place in the final. In the final, she lost to Kristýna Plíšková 3-6, 6-3, 6-2. Despite the loss, she climbed back inside the top-200 and recorded her first set of consecutive wins since the 2012 Hansol Korea Open.
Competing at the 2013 Internationaux Féminins de la Vienne as a wildcard, she beat Johanna Konta in the 1st round 7-5, 0-6, 7-6(5). In the 2nd round, Paszek lost to 5th seed Alexandra Cadanțu 6-4, 6-3. At the 2013 Aegon GB Pro-Series Barnstaple, Paszek lost in the 2nd round to 7th seed Kristýna Plíšková 6-1, 6-4.
Paszek began her season at the 2014 ASB Classic. She lost in the 1st round to 5th seed Jamie Hampton 1-6, 6-0, 6-3. Having failed to defend the previous year's second round points, her ranking dropped outside the top-200 and she elected to contest a $25,000 ITF event in Rancho Santa Fe, where she rebounded by winning the tournament. The following week, she advanced to another $25,000 final in Surprise, this time holding 14 match points before succumbing to 4th seed Jovana Jakšić of Serbia.
Paszek continued to participate in lower-level ITF events and reached her next final at a $25,000 event in Wiesbaden, bowing out to Ekaterina Alexandrova in three sets. At the French Open, Paszek qualified for the main draw, without dropping a set in all three qualifying matches. In the first round of the main tournament, she was pitted against Alison Van Uytvanck and defeated the Belgian to advance to the second round. Her run was ended there, however, as she went down to recent Australian Open finalist Dominika Cibulková in a straight-sets encounter.
She had a mediocre grass court season, winning just four matches in her Wimbledon warm-up tournaments, but did qualify for Wimbledon before losing there to 24th seed Kirsten Flipkens in a tough first-round match. She would proceed to play a slew of hard court events for the remainder of the year, but was not able to maintain form and only won four matches before the season's close. Paszek would end the year ranked world number 133.