Diyas has won one WTA title at 2017 Japan Women's Open. On 12 January 2015, she reached her best singles ranking of world number 31. On 8 June 2015, she peaked at world number 89 in the doubles rankings.
Playing for Kazakhstan at the Fed Cup, Diyas has a win-loss record of 8–2.
Diyas played her first professional tournament at a $100K ITF event in Bratislava, losing in the first round of qualifying. She did not play any more tournaments in 2007.
In 2008, Diyas played three tournaments, losing in qualifying of the first two events. She won her first title at a $25K tournament in Astana, where as a wildcard she defeated Tetyana Arefyeva in the final.
In 2009, Diyas battled through qualifying and advanced to two quarterfinals in Gifu and Fukuoka. She won her second title beating second seed Katalin Marosi to win another $25K tournament in Stuttgart. The best result of the year came at a WTA tournament in Prague, where she advanced to the quarterfinals with straight-set wins over Kristina Mladenovic and Petra Kvitová. Diyas went on to lose to Iveta Benešová. In September, she played her first grand slam, losing to Chang Kai-chen of Taiwan in the first round of the US Open Women's Singles qualifying. She ended her season playing three tournaments in Japan with modest results.
In 2010, she continued to rise up the rankings. Following mixed results for the first half of the year, she reached the final at Rome, losing to Patricia Mayr-Achleitner. Diyas played two more quarterfinals and one semifinal before reaching the quarterfinals of the Premier-level Kremlin Cup in Moscow. She qualified into the main draw and defeated World No. 49 Gisela Dulko in the first round. She then achieved the biggest win of her career by defeating top seed and World No. 7 Jelena Janković in the second round. However, she lost easily to Maria Kirilenko in the next match.
In 2011, Diyas reached the final at Kunming. She then reached the semifinals at Wenshan but did not reach another quarterfinal for the rest of the year.
At the start of 2012, Diyas was ranked No. 352. She made two quarterfinals and one semifinal. In June, she won her third title in Bukhara, not dropping a set the whole tournament. Later that year, she reached the final of a $25K event in Taipei. The next week, she participated in a new WTA 125 event, also in Taipei. She drew top seed Peng Shuai and defeated the World No. 40 in straight sets. She followed this up by dismantling Varatchaya Wongteanchai, losing just one game. She then lost in the quarterfinals to Kurumi Nara, which would mark her final quarterfinal of the season.
2013 was successful for Diyas – she began the year ranked World No. 264 and would finish the year ranked more than 100 spots higher. She began the year contesting many ITF events with modest results, before recording a big win over Kristýna Plíšková in the first round of the Malaysian Open. Her only tournament win came in Makinohara, where she defeated talented Swiss junior Belinda Bencic to clinch victory. She then advanced to another final in Taipei, but lost to Paula Kania in straight sets. She competed in 1 more event before finishing the year ranked World No. 163.
2014 was Diyas' breakthrough season. She made her season debut in Hong Kong, reaching the final of an 25K ITF tournament, losing in the final to Elizaveta Kulichkova of Russia. She then entered Australian Open qualifying, registering a hard-fought three-set win over Aleksandra Krunić in the first round. She then came from a set down to defeat Andreea Mitu and get to the finals, where she beat Canadian Stéphanie Dubois. This resulted in the first main draw berth in her career, as well as her first Grand Slam (tennis) entry. In the first round of the main draw, she proceeded to beat fellow qualifier Kateřina Siniaková. In the second round, she breezed past World No. 52 Marina Erakovic to book her place in the third round. Diyas' run was ended there; however, as she went down to World No. 11 Simona Halep in straight sets. Nevertheless, her two early round wins helped boost her ranking to a career-high No. 112. Following the Australian Open, Diyas lost qualifying matches in Pattaya City and Doha. She would bounce back quickly, though, as she then easily won a 50K ITF event in Quanzhou.
She then traveled to the United States to compete in the Miami, qualifying for the main draw and getting past Alexandra Cadanțu before losing to Sloane Stephens in the second round. Although she failed to qualify for the Family Circle Cup, she played at the Malaysian Open and advanced to the quarterfinals – her first WTA quarterfinal since the 2010 Kremlin Cup.
Diyas then went to Europe but lost early in the first 2 tournaments contested. At the French Open warm-up event in Strasbourg; however, she returned to form with a win over World No. 22 Kirsten Flipkens in the first round. She followed it up by dispatching Ajla Tomljanović before having to retire in her quarterfinal match. Holding a world ranking of No. 86, Diyas was granted a spot in the main draw of the French Open, but got a tough draw and was knocked out by Petra Kvitová in the first round. At the ITF grass court tournament in Nottingham, she advanced to the final but was narrowly beaten by Kristýna Plíšková.
She played one more grass court event before entering Wimbledon. There, she got her first ever win at Wimbledon by defeating Frenchwoman Kristina Mladenovic in a rain-delayed straight sets match. She followed this up with three-set wins against 15th seed Carla Suárez Navarro and former world number 2 and 2010 Wimbledon finalist Vera Zvonareva, before losing in straight sets to 3rd seed Simona Halep in the fourth round.
In August 2014 in her best result at the US Open to date, unseeded Diyas advanced to the women's singles third round where she lost in straight sets to 17th seed Ekaterina Makarova of Russia, earning $105,090.
In October 2014 Diyas reached get first WTA final at the tournament in 2014 Japan Women's Open where she lost to Samantha Stosur in straight sets.
In January, Diyas was seeded 31 in singles at the 2015 Australian Open. She beat qualifier Urszula Radwańska of Poland in three sets in the first round and then unseeded Slovak Anna Karolína Schmiedlová in the second round in three sets, but lost her third round match against number two seed and finalist Maria Sharapova in straight sets. Diyas also played doubles with South African Chanelle Scheepers and they advanced to the second round before losing to the sixteenth-seeded German team of Julia Görges and Anna-Lena Grönefeld in straight sets.
At the 2015 French Open, Diyas was seeded 32. She defeated qualifier Dinah Pfizenmaier in straight sets but eventually lost to Alison Van Uytvanck in the second round.
Prior to Wimbledon, Diyas was defeated by lower ranked players in two warm-up tournaments, losing to 129th ranked American Sachia Vickery in Nottingham and to 146th ranked Johanna Konta of Great Britain in Eastbourne. Diyas, however, reached the round of 16 at Birmingham, by defeating Kateryna Bondarenko in straight sets and through the withdrawal of Victoria Azarenka. Diyas subsequently lost to 12th ranked Czech Karolína Plíšková 6-2, 6-2.
Despite the slow start on grass that left her unseeded at the 2015 Wimbledon, Diyas managed to advance to the fourth round for the second consecutive year. Diyas beat 24th seed Flavia Pennetta, qualifier Aliaksandra Sasnovich and 14th seed Andrea Petkovic. However, Diyas' stealthy run at Wimbledon was ended by the 4th seed Maria Sharapova, 6-4, 6-4.
Her hardcourt season however did not fare as well as her performance on grass. Diyas failed to win in all her pre-US Open tournaments. In Washington, Diyas had to retire against Lauren Davis after trailing 7-5, 2-1. She lost to lucky loser Julia Görges 2-6, 6-1, 7-5 in Toronto, to Venus Williams 7-6 (6) 6-4 in Cincinnati and to Irina-Camelia Begu in New Haven 7-5 5-7 6-2 - all in the first round.
At the first round of the 2015 US Open, Diyas was defeated by Polona Hercog 6-2, 7-5. This meant that she failed to repeat her third round appearance in the previous year.
Diyas suffered a wrist injury in Round 1 of Wimbledon and underwent surgery. She did not play in any tournaments in 2016 after that. As a result, she fell out of Top 100.
Diyas' attempt to return from her injury started with a series of losses. She lost in the opening rounds of her first four tournaments of the season before scoring her first wins at Quangzhou, reaching quarterfinals and losing to Zheng Saisai 6-2, 6-0. She then won her first ITF title since June 2014 in a 25K tournament in Nanning. At Zhengzhou, she managed to reach quarterfinals before losing to the first seed Shuai Peng 6-3, 6-3. At Anning, she reached final but lost to Saisai again 7-5, 6-4. At Gifu she lost in the first round to Luksika Kumkhum. She then lost to another returning player Magdalena Rybarikova twice, in Fukuoka and Surbiton. Diyas then failed to qualify for the main draw of French Open as she lost to Bethanie Mattek-Sands 6-4, 6-1, despite having defeated Sachia Vickery and Polona Hercog in the first two qualifying rounds.
Diyas then won a 100K tournament in Manchester, scoring victories against Emily Webley-Smith, Arina Rodionova, Magdalena Frech, Naomi Broady and Aleksandra Krunic without dropping a set.
At 2017 Wimbledon Diyas was given a wildcard to the main draw. She won her first two round matches against Han Xinyun 6-3, 6-4 and Arina Rodionova 6-4, 7-6. She lost to another returning player Petra Martic in the third round 7-6, 6-1.
At 2017 Japan Women's Open, Diyas won all her qualifying matches to reach the main draw. She went on to score victories against higher-ranked players such as local favourite Misaki Doi, top 30 player Shuai Zhang, compatriot Yulia Putintseva and defending champion Christina McHale to reach final. She eventually beat fellow qualifier Miyu Kato 6-2, 7-5 to win her first ever WTA title.
Diyas is primarily an aggressive baseliner whose game is centered around powerful and accurate groundstrokes. Her forehand, which generates a considerable amount of pace, is often used to move her opponents around the court and out of position, which therefore allows her to dominate and win points from or around the back of the court. Her serve, while not necessarily a weapon in her arsenal, is quite effective when placed properly and she employs a tactic of a delayed service motion, which often disables her opponents from appropriately timing a return. While not a great mover on court, she is able to somewhat compensate for it with her tenacious fighting qualities.
Srixon sponsors Diyas, providing her racquets, clothing and shoes.