Australian Open finalist Petra Kvitova has been eliminated from the St. Petersburg Ladies Trophy after losing to eighth-seeded Donna Vekic 6-4 6-1 in the quarter-finals.

The world No.2 landed only 48 per cent of her first serves, double-faulted six times and was broken five times on FRIDAY.

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 either third-seeded Daria Kasatkina or Vera Zvonareva in the semi-finals.

Fourth-seeded Aryna Sabalenka reached the semifinals by beating Russian qualifier Ekaterina Alexandrova 6-3 6-4.

She will next play either Kiki Bertens or Anastasia Pavlyuchenkova.