Silicon Valley Classic: Fifth seed Donna Vekic stuns former World No 1 Victoria Azarenka to enter third round

Former World No 1 Victoria Azarenka paid the price for her erratic serve as fifth-seeded Donna Vekic prevailed 6-4, 6-3 on Thursday in the second round of the Silicon Valley Classic in San Jose.

Azarenka, who is coming off a third-round loss at Wimbledon last month, committed seven double faults and had her service broken five times in the contest.

She showed life in the second set as she seized a 2-0 lead, but 23-year-old Croatian Vekic had her way in the end to set up a quarter-final match with Kristie Ahn.

Ahn reached the quarter-finals by converting seven break points to upset third-seeded Belgian Elise Mertens 6-3, 6-3.

Fourth seed American Amanda Anisimova, a 17-year-old, beat compatriot Madison Brengle 6-2, 6-2 to reach the next round matchup with China’s Saisai Zheng who routed Danielle Collins 6-2, 6-0.