Klára Koukalová

2003

Koukalová made her Grand Slam debut at the 2003 Australian Open, defeating fellow qualifier and Grand Slam debutante Maria Sharapova in the first round before going on to upset sixth-seed Monica Seles in the second round. Koukalová's run ended in the third round.

2006

In January 2006, she played comeback player Martina Hingis, at the WTA tournament in Gold Coast, Queensland, Australia, where she lost in the second round. Koukalová was seeded 29th at the 2006 Australian Open, but lost in the first round to Ekaterina Bychkova. In that year, Koukalová had ten first-round losses in singles and failed to win a doubles match.

2008

In 2008, Koukalová reached the final of the inaugural Cachantun Cup in Chile. She played the top seed Flavia Pennetta, but was forced to retire due to a sprained ankle. This also forced her to withdraw from the next tournament in Bogotá, where she had made the quarterfinals in 2007.

2009

Koukalová's biggest win came at the 2009 Andalucia Tennis Experience in Marbella, Spain. She defeated world number 1 and ten-time Grand Slam champion Serena Williams in three sets. Williams was also her first round opponent at the 2009 French Open, where Koulalová lost.

2010

Koukalová gained another good win over a top-5 player, defeating Dinara Safina in the first round of the 2010 Mutua Madrilena Madrid Open.

In the first round of the 2010 Polsat Warsaw Open, Koukalová caused a big upset by defeating fourth seed and world number 14 Marion Bartoli. She was then defeated by world number 205 Gréta Arn in the second round.

At the 2010 Wimbledon Championships, Koukalová advanced to the fourth round for the first time at a Grand Slam. She scored upset wins over 18th seed Aravane Rezaï and tenth seed Flavia Pennetta, before falling to qualifier Kaia Kanepi.

Koukalová made the final at the 2010 e-Boks Danish Open, where she lost to then world number 3 Caroline Wozniacki. Koukalová defeated Rossana de los Rios, Tatjana Malek, Sorana Cîrstea, and Li Na en route to the final. After this tournament, she could not match her performance as she went on to do poorly in her last four tournaments, only advancing to the second round at the 2010 Generali Ladies Linz, where she lost to Patty Schnyder.

2011

Koukalová started her 2011 season at the Hobart International, after having to withdraw from the Brisbane International. She made the semifinals in Hobart, upsetting the top seeded Marion Bartoli in the quarterfinals, before falling to her doubles partner Jarmila Groth.

At the 2011 Australian Open, Koukalová defeated American Melanie Oudin in three sets in the first round, before falling to fellow Czech Lucie Šafářová in three sets in the second round. This was Koukalová's first victory at the Australian Open since 2003.

Koukalová was seeded 31st for the 2011 French Open, her first seeding at a Grand Slam since 2006. She was upset in the first round by Taiwanese qualifier Chan Yung-jan.

After her defeat at Roland Garros, Koukalová traveled to Copenhagen to defend her finalist points from the year before. Seeded second, she was upset in the first round by German Kathrin Wörle.

Koukalová then returned to the site of her greatest Grand Slam accomplishment, Wimbledon. Unseeded, she came from a set down to defeat British wildcard Emily Webley-Smith in the first round. In the second round, she avenged her Australian Open loss by upsetting 31st seed Lucie Šafářová in three sets. In the third round, Koukalová fell to eventual finalist Maria Sharapova.

After Wimbledon, Koukalová made the semifinals in Budapest, where she lost to the eventual champion Roberta Vinci, and then made the quarterfinals in Palermo, where she lost to eventual finalist Polona Hercog.

2013

Koukalová played in the 2013 US Open and lost in the first round to Hsieh Su-wei. Remarkably, this was her tenth first round loss at the US Open out of 10 appearances in the main draw.

2014

Zakopalová began her year by competing at the 2014 Shenzhen Open. As the 3rd seed and last year finalist, she defeated Donna Vekić in the 1st round 6-3, 7-5. In the 2nd round, she lost to Patricia Mayr-Achleitner 7-6(2), 6-4. In doubles, Zakopalová and Monica Niculescu won the title defeating Lyudmyla Kichenok/Nadiia Kichenok 6-3, 6-4. Seeded 7th at the 2014 Hobart International, Zakopalová reached the final by defeating Yvonne Meusburger 7-5, 6-2; Shuai Zhang 6-1, 6-2; Alison Riske 6-4, 7-5; and 1st seed Samantha Stosur 6-3, 6-2. In the final, Zakopalová lost to qualifier Garbiñe Muguruza 6-4, 6-0. However, in doubles, Zakopalová and Niculescu won the title defeating Lisa Raymond/Shuai Zhang 6-2, 6-7(5), 10-8. At the 2014 Australian Open, Zakopalová lost in the 1st round to 17th seed Samantha Stosur 6-3, 6-4.

At the 2014 Open GDF Suez, Zakopalová defeated wildcard Caroline Garcia in the 1st round 7-6(4), 6-2. In the 2nd round, she lost to 4th seed and 2012 Open GDF Suez Champion Angelique Kerber 6-2, 7-5. Playing against Spain at the 2014 Fed Cup World Group, Zakopalová won her 1st rubber over María Teresa Torró Flor 6-3, 2-6, 6-1. She lost her 2nd rubber to Carla Suárez Navarro 1-6, 6-3, 6-3. In the end, the Czech Republic defeated Spain 3-2. At the 2014 Qatar Total Open, Zakopalová beat Elina Svitolina in the 1st round 6-2, 6-4. In the 2nd round, she upset 9th seed Ana Ivanovic 4-6, 6-1, 6-3. In the 3rd round, Zakopalová lost to 6th seed and eventual finalist Angelique Kerber 6-2, 6-3. At the 1st edition of the 2014 Rio Open, Zakopalová was the 1st seed. She reached the final by defeating Mariana Duque Mariño 6-4, 6-4; Sílvia Soler Espinosa 6-4, 6-1; Katarzyna Piter 6-4, 6-0; and Brazilian Teliana Pereira 6-2, 6-1. In the final, Zakopalová lost to 5th seed Kurumi Nara 6-1, 4-6, 6-1. Zakopalová, as the 3rd seed, reached the final of the 2014 Brasil Tennis Cup by defeating Donna Vekić 6-3, 6-3; qualifier Alizé Lim 6-3, 6-3; qualifier Alexandra Dulgheru 6-3, 5-2 ret.; and 1st seed Carla Suárez Navarro 6-3, 3-6, 6-2. In the final, Zakopalová defeated 2nd seed Garbiñe Muguruza 4-6, 7-5, 6-0 to win her 3rd WTA singles title. At the 2014 BNP Paribas Open, Zakopalová was the 28th seed; she also received a bye into the 2nd round. In the 2nd round, she lost to compatriot Karolína Plíšková 7-5, 6-2. At the 2014 Sony Open Tennis, Zakopalová was the 27th seed; she again received a bye to the 2nd round. She lost in the 2nd round to Caroline Garcia 7-6(3), 7-6(3). After Miami, Zakopalová switched back to her maiden name, Koukalová.

At the 2014 BNP Paribas Katowice Open, Koukalová was seeded 5th. She defeated Magda Linette in the 1st round 6-4, 6-3 and Annika Beck in the 2nd round 4-6, 6-3, 6-1. In the quarterfinals, Koukalová lost to 4th seed and eventual champion Alizé Cornet 6-2, 0-6, 6-2. In doubles, she and Niculescu reached the final where they lost to Yuliya Beygelzimer/Olga Savchuk 6-4, 5-7, 10-7.

Koukalová began her clay court season at the 2014 Porsche Tennis Grand Prix. She lost in the 1st round to 8th seed Sara Errani 6-3, 6-4. At the 2014 Mutua Madrid Open, Koukalová lost in the 1st round to 8th seed and eventual champion Maria Sharapova 6-1, 6-2. Playing at the 2014 Sparta Prague Open in her country, Koukalová lost in the 1st round to eventual champion Heather Watson 6-2, 6-4. Seeded 3rd at the 2014 Nürnberger Versicherungscup, Koukalová lost in the 1st round to Polona Hercog 1-6, 6-2, 6-1. Seeded 30th at the 2014 French Open, Koukalová lost in the 1st round to María Teresa Torró Flor 7-6(4), 6-2.

Koukalová began her grass court season at the 2014 Aegon Classic. Seeded 6th, Koukalová also received a 1st round bye. In the 2nd round, she defeated Virginie Razzano 5-7, 7-6(5), 7-6(0). In the 3rd round, she defeated Coco Vandeweghe 3-6, 7-6(3), 6-4. In the quarterfinals, Koukalová lost to 1st seed and eventual champion Ana Ivanovic 6-1, 6-4.

In September 2016 Koukalová announced her retirement from professional tennis.

Personal life

On 6 June 2006, Klára married Czech footballer Jan Zakopal, but they divorced in January 2014. From June 2006 to March 2014, she used her married name Zakopalová while competing, switching back to Koukalová in April 2014.