Petra Kvitova of Czech Republic reacts during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match against Donna Vekic of Croatia in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
ST. PETERSBURG, Russia (AP) - Australian Open finalist Petra Kvitova struggled with her serve and was eliminated from the St. Petersburg Ladies Trophy after losing to eighth-seeded Donna Vekic 6-4, 6-1 in the quarterfinals on Friday.
The second-ranked Kvitova landed only 48 percent of her first serves, double-faulted six times, and was broken five times.
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. It was Vekic's fifth match in that time.
Vekic will next face veteran Vera Zvonareva in the semifinals after she beat fellow Russian Daria Kasatkina 6-3, 7-6 (3).
The 12th-ranked Kasatkina has yet to win a match this year after four losses and a single walkover over the injured Maria Sharapova.
Fourth-seeded Aryna Sabalenka reached the semifinals by beating Russian qualifier Ekaterina Alexandrova 6-3, 6-4. She will next play Kiki Bertens, who beat Anastasia Pavlyuchenkova 6-2, 3-6, 6-0. That was a rematch after Pavlyuchenkova knocked Bertens out of the Australian Open second round.
___
More AP Tennis: https://www.apnews.com/apf-Tennis and https://twitter.com/AP_Sports
Petra Kvitova of Czech Republic returns the ball to Donna Vekic of Croatia during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Donna Vekic of Croatia serves during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match against Petra Kvitova of Czech Republic in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Donna Vekic of Croatia returns the ball to Petra Kvitova of Czech Republic during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Aryna Sabalenka of Belarus returns the ball to Ekaterina Alexandrova of Russia during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Ekaterina Alexandrova of Russia returns the ball to Aryna Sabalenka of Belarus during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Vera Zvonareva of Russia returns the ball to Daria Kasatkina of Russia during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Daria Kasatkina of Russia returns the ball to Vera Zvonareva of Russia during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press
Kiki Bertens of Netherlands returns the ball to Anastasia Pavlyuchenkova of Russia during the St. Petersburg Ladies Trophy-2019 tennis tournament quarter final match in St.Petersburg, Russia, Friday, Feb. 1, 2019. (AP Photo/Dmitri Lovetsky)
The Associated Press