Kiki Bertens

Bertens started off her clay-court season at the Charleston Open as defending champion and reached the third round before losing against Maria Sakkari in straight sets. After that, Bertens reached the semifinals at the Porsche Tennis Grand Prix in Stuttgart, losing in three sets to Petra Kvitová. However, she bounced back at the Madrid Open, where she cruised through her first three matches against Kateřina Siniaková, Jeļena Ostapenko, and Anastasija Sevastova. In the quarterfinals, she avenged both the loss in last year’s final and the loss in Stuttgart against Kvitová, beating the Czech, losing just five games. In the semifinals, she beat Sloane Stephens for the first time in her career, reaching a second consecutive Madrid final. There, she beat world No. 3 Simona Halep in straight sets, winning her first Premier Mandatory title, beating four former Grand Slam champions along the way and becoming the first to win Madrid without dropping a set. By doing so, she reached a new career-high ranking of No. 4.

Kiki's older sister Joyce works as a business consultant and helps manage her finances. Kiki married her physiotherapist Remko de Rijke on November 30th 2019.

Kiki Bertens was named "Most Improved Player of the Year" for 2018 by the WTA.

After Wimbledon, Bertens decided not to defend her title on the clay of Gstaad. She started the hard-court season in Montreal at the Canadian Open where she made an impressive run, beating for the first time two top-ten players on hard court. She defeated ninth seed Karolína Plíšková and eighth seed Petra Kvitová before losing to 15th seed Ashleigh Barty in the quarterfinals, her best performance in Montreal. The following week, she won the biggest title of her career in Cincinnati, beating top-10 players Wozniacki, Svitolina, Kvitová and Halep along the way.

In 2015, she changed coaches from Christiaan de Jong to Raemon Sluiter.

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.

At the 2014 French Open, she reached the fourth round as a qualifier in which she was defeated in three sets by Andrea Petkovic.

Seeded fourth for qualifying at the Open GdF Suez, 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 after wins over Tamira Paszek, fourth seed Dominika Cibulková, and sixth seed Lucie Šafářová. In the semifinals, Bertens faced top-seed Sara Errani. Errani led 5–0 in the first set when Bertens retired due to a back injury.

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 Korea Open, Bertens was seeded second, but lost in the first round against compatriot Richèl Hogenkamp. She lost in the second round of the Wuhan Open to qualifier Varvara Lepchenko, and in the first round of both the China Open and Austrian Open. After a string of early-round losses, Bertens reached the quarterfinals of the Luxembourg Open. Seeded second, she beat Denisa Allertová in the first round, in the second she beat Andrea Petkovic, but fell to the eventual winner Carina Witthöft. Bertens competed in by far her biggest final of her career at the WTA Finals with partner Johanna Larsson. They had a big win over the second seeds Ekaterina Makarova and Elena Vesnina in the semifinals. However, they lost to Tímea Babos and Andrea Sestini Hlaváčková in the final. Bertens ended the year ranked 31st, down from 22nd the year prior. However, her ranking in doubles reached a new career high at 19th.

In the qualifying for the WTA event in Fes, she beat Moroccan wild card Intissar Rassif without dropping a game. She reached her first WTA final in this tournament, defeating Urszula Radwańska, sixth seed Chanelle Scheepers, Garbiñe Muguruza, and fifth seed Simona Halep along the way. Prior to this tournament, 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.

Kiki Bertens (Dutch pronunciation: [ˈkiki ˈbɛrtəns] ; born 10 December 1991) is a Dutch tennis player who turned professional in 2009. Her highest WTA singles ranking is No. 4, which she reached on 13 May 2019, becoming the highest ranked Dutch female player ever. Her career high in doubles is world No. 16, achieved in April 2018. To date, she has won ten singles titles and ten doubles titles on the WTA Tour including 2018 Western & Southern Open and 2019 Mutua Madrid Open. Bertens is widely regarded as a clay-court specialist, but also is successful on hard courts. Raemon Sluiter has been her coach. On 1 November 2019 she announced on Instagram that Raemon Sluiter would no longer be her coach and Elise Tamaëla would be her new coach. Tamaëla was her interim coach at the time.

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.