SHENZHEN, China (AP) Second-seeded Petra Kvitova had six aces in a 6-1, 6-2 victory over Bojana Jovanovski on Tuesday in the second round of Shenzhen Open.

The Czech broke Jovanovski twice in the first set before saving three break points in the second.

Also, Zheng Saisai of China defeated Polona Hercog of Slovenia 6-3, 2-6, 6-2, and fourth-seeded Zarina Diyas of Kazakhstan beat Timea Babos of Hungary 6-3, 6-4.