Eighth seed Donna Vekic beat Russian Veronika Kudermetova 6-4, 6-3 in the second round of the St Petersburg Ladies Trophy on Wednesday. The Croatian broke world number 108 Kudermetova four times, in a match that lasted just over an hour and a quarter. Vekic will next face Australian Open finalist Petra Kvitova in the quarter-finals. Top seed Kvitova won eight straight games to take control of the match before needing a tiebreaker to finally beat Victoria Azarenka 6-2, 7-6 (7-3).