Kiki Bertens beat Elena Rybakina 6-1, 6-3 to retain the St Petersburg Ladies Trophy on Sunday.
St. Petersburg Ladies' Trophy: Australian Open finalist Petra Kvitova eliminated by Donna Vekic; Aryna Sabalenka into semi-finals
Kvitova, the defending St. Petersburg champion who lost to Naomi Osaka in the Australian Open final, was playing in her 14th match in 24 days
St Petersburg Ladies' Trophy: Second-seed Kiki Bertens dispatches Ysaline Bonaventure to enter quarter-finals
The 27-year-old Kiki Bertens will next meet Russia's Anastasia Pavlyuchenkova, who upset sixth-seeded former French Open champion Jelena Ostapenko of Latvia 6-4, 6-4
31-year-old Maria Sharapova has been struggling back to elite fitness since watching from the sidelines during her 15-month doping ban that ended in 2017
St Petersburg Ladies Trophy: Petra Kvitova outplays defending champion Kristina Mladenovic to clinch title
Petra Kvitova prevailed 6-1, 6-2 against defending champion Kristina Mladenovic on Sunday to claim the St Petersburg Ladies Trophy, her 21st WTA crown.
St Petersburg Ladies' Trophy: Defending champion Kristina Mladenovic sets up title clash with Petra Kvitova
Fourth seed Mladenovic, ranked 10th in the world, made another step to retaining her only WTA title with a win over 20-year-old Daria Kasatkina.
St Petersburg Ladies' Trophy: Caroline Wozniacki ousted by Daria Kasatkina, Petra Kvitova thumps Jelena Ostapenko
Fresh from her first ever Grand Slam title Wozniacki had raced to the quarter-finals but had been expecting Kasatkina to give her a difficult time.
St Petersburg Ladies' Trophy: Caroline Wozniacki races into quarter-finals; Kristina Mladenovic ends losing streak
Australian Open champion Caroline Wozniacki handed 16-year-old Russian wild card Anastasia Potapova a 6-0, 6-1 rout at the St Petersburg on Thursday.