Second seed Venus Williams was upset by big-serving German Sabine Lisicki, losing 6-4, 7-6 in the third round of the Family Circle Cup in California on Thursday. Chinese 10th seed Peng Shuai was stopped by fifth seed Caroline Wozniacki, losing 6-3, 6-4. But Peng still equaled her best result in this clay-court event.

Peng produced poor first serves in the first set. She was down at 2-5 in the second set before rallying to close the gap at 4-5 but Wozniacki proved her the more experienced one as the Danish world number 12 served for the match.

2004 Champion Venus, who had to battle the previous day before beating Indian Sania Mirza in three sets, lost the match in 87 minutes after the 16th-seeded German took the tiebreak 7-5.

In another upset on the stadium court, Hungarian left-hander Melinda Czink eliminated fourth-seeded Russian Nadia Petrova 3-6, 6-4, 7-5 in more than two hours.

Elena Dementieva of Russia returns a volley during her women's tennis match against Varvara Lepchenko of the U.S. at the Family Cup Circle Tennis Tournament in Charleston, South Carolina April 16, 2009

Top-seeded Russian Elena Dementieva swept aside American Varvara Lepchenko 6-1, 6-1. Sixth-seeded Frenchwoman Marion Bartoli booked her place in the last eight with a 6-4, 6-1 demolition of American Melanie Oudin while seventh-seeded Dominika Cibulkova of Slovakia recovered to beat Russian Anastasia Rodionova 6-7, 6-2, 6-3.