Kiki Bertens (; born 10 December 1991) is a Dutch former professional tennis player. Her career-high singles ranking was world No. 4, which she reached on 13 May 2019, becoming the highest-ranked Dutch female player ever. Her career-high doubles ranking of world No. 16, she achieved in April 2018. She won ten singles and ten doubles titles on the WTA Tour, including 2018 Cincinnati Open and 2019 Madrid Open. Bertens was widely regarded as a clay court specialist, but also was successful on hardcourt.
Early life and background Bertens was born on 10 December 1991 in Wateringen near The Hague, but grew up in the town of Berkel en Rodenrijs. She has two sisters, one older and one younger. Bertens started playing tennis at age six at ATV Berkenrode, a tennis club where her aunt and uncle played. She has been coached by Martin van der Brugghen at the club since she was seven years old. Van der Brugghen recognized her ability and continued to coach her primarily to help her reach her potential. He said: "In the youth we have supported her very much. I taught her for little money because I find it interesting to see how far you can get with someone." Bertens received little support from the Dutch tennis federation. She did not play on the ITF Junior Circuit except for one appearance at the Junior Fed Cup in 2007.
Senior career 2012: First WTA Tour title Bertens started the year playing the qualifiers for the Australian Open. In the first round against top seed Vesna Dolonts, she won the first ten games before Dolonts retired. In the second, Bertens lost to Olga Savchuk in a close three-set match. The following week, in a $25k event in Andrézieux-Bouthéon, Bertens retired with a thigh injury in the first round against Corinna Dentoni.
She played in the Fed Cup for the Dutch team, competing in Group 1 of Europe/Africa. She partnered with Demi Schuurs in the doubles match against the Portuguese team of Bárbara Luz and Margarida Moura and won in two sets. Bertens won her singles rubber against Estonia's Eva Paalma and with Michaëlla Krajicek double-bageled Anett Kontaveit and Tatjana Vorobjova. Late February she played the qualifications for WTA tournament of Acapulco. She defeated Mexican wild card Ana Paula de la Peña in the first round but lost in the second qualification round to Sesil Karatantcheva.
At a $25k event in Irapuato, Mexico, Bertens won her second ITF singles title, beating Yaroslava Shvedova in the final, propelling her to a new career high in singles ranking. The following week, she made it to the quarterfinals of the $25k tournament in Poza Rica, but her winning streak was snapped by Jana Čepelová. At the $25k tournament in Bath the week afterwards, Bertens won the title, defeating Annika Beck in the final in three sets, her fourth three-set match in a row. Bertens failed to qualify for the WTA Tour tournament in Copenhagen, falling to Johanna Konta.
In the qualifying for the WTA Tour event in Fes, she beat Moroccan wildcard Intissar Rassif without dropping a game. She reached her first WTA tournament final in this tournament, defeating Urszula Radwańska, sixth seed Chanelle Scheepers, Garbiñe Muguruza, and fifth seed Simona Halep along the way. Prior to this event, she had never won a WTA singles match in the main draw. In the final, she defeated Laura Pous Tió, winning the last eight games. She became the first Dutch female player since Michaëlla Krajicek in 2006 to win a WTA singles tournament.
At the French Open, Bertens was seeded No. 1 in qualifying and defeated Annika Beck in the first qualifying round, saving a matchpoint in the third set. She defeated Olga Puchkova in the second round and outclassed Mădălina Gojnea in the final qualifying round. This meant Bertens' first main-draw appearance at a Grand Slam tournament. In the first round, she lost in three sets to Christina McHale.
Bertens debuted at Wimbledon in her first-round match against the No. 19 seed Lucie Šafářová and won in two sets, her first win at a Grand Slam event. In the second round, she lost to Yaroslava Shvedova in straight sets. Bertens then made a brief appearance at an ITF tournament in Biella, but lost to homeplayer Nastassja Burnett in the first round. This was followed by first-round losses in Palermo and Båstad to Alexandra Cadanțu and Polona Hercog, respectively.
Bertens returned to form during the American hardcourt circuit. In Montreal, she qualified by defeating Vladimíra Uhlířová, Zhang Shuai, saving two matchpoints, and Alexa Glatch. In the main draw, Bertens caused an upset, defeating former world No. 3 (then ranked 22) Nadia Petrova, coming back from a large deficit. In the second round, Caroline Wozniacki proved too strong, and Bertens lost in straight sets. Like in Montreal, Bertens qualified for the main draw in Cincinnati, defeating Aravane Rezaï and Yulia Putintseva. However, in the main event she succumbed to fellow qualifier Sesil Karatantcheva. In Dallas, she retired with a shoulder injury against Polona Hercog.
At the US Open, Bertens exacted revenge on Christina McHale, knocking out the American in the first round but suffering a three-set loss to Olga Puchkova in the second round. Bertens stated afterwards she had been nervous during the match. At the WTA tournament in Seoul, Bertens defeated Vania King and Sílvia Soler Espinosa from Spain to reach the quarterfinals. She faced Estonian Kaia Kanepi next and lost in straight sets. After a second-round appearance in Linz she ended her season with a first-round loss in Luxembourg due to fatigue.
2013–2015
Starting the year ranked No. 63, her first tournament was the Auckland Open. In the first round, she defeated Svetlana Kuznetsova in three sets. In the second round, she beat Heather Watson. In the quarterfinals, Bertens was defeated by Jamie Hampton. Seeded fifth for qualifying at the Sydney International, she lost in the first round of qualifying to Misaki Doi. Ranked 60 at the Australian Open, Bertens was defeated in the first round by Lucie Hradecká.
Seeded fourth for qualifying at the Paris indoor event, Bertens reached the final round where she lost to Virginie Razzano. However, she entered the main draw as a lucky loser. She reached the semifinals with wins over Tamira Paszek, fourth seed Dominika Cibulková, and sixth seed Lucie Šafářová. In the semifinals, Bertens faced top-seeded Sara Errani. Errani led 5–0 in the first set when Bertens retired due to a back injury.
At the 2014 French Open, she reached the fourth round as a qualifier in which she was defeated in three sets by Andrea Petkovic.
In 2015, she changed coaches from Christiaan de Jong to Raemon Sluiter.
2016: WTA Tour title and a major semifinal
Bertens started the year in Auckland, where she entered the main draw as a qualifier. She lost in the first round to Barbora Strýcová. At the Hobart International, she reached the quarterfinal, losing there to Dominika Cibulková. She lost in the first round of the Australian Open to Laura Siegemund.
Bertens then earned two important wins in the Fed Cup tie against Russia, beating Ekaterina Makarova and Svetlana Kuznetsova. They ended up beating the 2015 finalists. After that, Bertens had early defeats in Acapulco (losing to Naomi Osaka in the first round) and in Monterrey (losing in the last round of the qualifying to Pauline Parmentier). After entering Indian Wells' main draw as a qualifier, she lost in the first round to CoCo Vandeweghe. Prior to the Miami Open, she played at the San Antonio Open where she reached the round of 16. Then, in Miami, she once again reached the main draw through qualifying and earned wins over Zheng Saisai and No. 25 seed Anastasia Pavlyuchenkova before retiring in the third set in her third-round match against Angelique Kerber.
Playing for the Netherlands at the Fed Cup semifinals against France, Bertens kept her winning streak by beating Caroline Garcia and Kristina Mladenovic, both in straight sets; nonetheless, it was not enough as France won the tie in the doubles decider. After that, she started her clay-court season with a semifinals run in Rabat, only losing to Marina Erakovic.
At Nuremberg, Bertens won her second WTA singles title by defeating Mariana Duque Mariño in the final in straight sets. In the second round, she had defeated top-seeded Roberta Vinci which was her first win against a top-10 player. And it was her first title since 2012. She also won the doubles title alongside Johanna Larsson.
At the French Open, Bertens avenged her Miami loss by upsetting No. 3 seed Angelique Kerber in three sets. She then beat Camila Giorgi, 29th seed Daria Kasatkina, 15th seed Madison Keys, and No. 8 seed Timea Bacsinszky en route to her first Grand Slam semifinal. In her semifinal match against the top seed Serena Williams, Kiki played with a left calf injury which made it difficult for her to move forward to Williams' drop shots. Bertens never took advantage of a medical time-out or took trainer treatment. Despite having two set points and being up by a break in both sets, she lost in straight sets. However, she entered the top 30 for the first time in her career.
Prior to Wimbledon, Bertens was scheduled to play at the Rosmalen Open; due to the same injury that harmed her left calf, she was forced to pull out of the tournament. After a few weeks of recovery, Bertens kicked off her campaign at the third Grand Slam event of the year and defeated Jeļena Ostapenko and Mona Barthel to reach the third round of the grass tournament for the first time. She then lost to Simona Halep.
Her next tournament was the inaugural Ladies Championship Gstaad, where she reached the final. She lost one set to Tamira Paszek en route. In the final, Bertens lost in three sets to Viktorija Golubic. Despite the defeat, she climbed to No. 21 in the rankings.
Despite winning her second title of her career this year and making it to the semifinals of the French Open, Bertens lost in the first round of six straight tournaments, notably including the Rio Olympics and US Open. As a result of her inconsistency, she decided not to compete at the Wuhan Open and China Open. She made her return at the Linz Open. However, she lost in the first round to Sorana Cîrstea but won the doubles with Johanna Larsson. Her next event was the Luxembourg Open. She had her best result since Wimbledon by making it to the semifinals, losing to Monica Niculescu. However, she did not go home empty handed. Bertens and Larsson won their second doubles title in a row. Bertens ended her season at the WTA Elite Trophy where she lost both of her matches with close scorelines, against Elina Svitolina and Elena Vesnina.
2017: Two WTA titles, Tour Championships doubles final
Bertens started her year off with a first-round loss to Lauren Davis at Auckland. However, Bertens and Larsson won the doubles title. Kiki was seeded first at Hobart. She had routine wins over Annika Beck and Galina Voskoboeva in the first two rounds, but lost to qualifier and eventual champion Elise Mertens. She continued to struggle during her next four tournaments, and lost in the first round of all of them including the Australian Open.
She then traveled to the United States for the Indian Wells and Miami Open, and lost to Timea Bacsinszky at Indian Wells in a hard-fought three-setter, and in the second round in Miami to qualifier Risa Ozaki.