DOHA, Qatar — Second-seeded Svetlana Kuznetsova was upset by Sybille Bammer and sixth-seeded Venus Williams lost to Dominika Cibulkova today in the third round of the Qatar Open.

Cibulkova used strong baseline play and broke serve twice in both sets to defeat Williams 6-3, 6-3 in their first meeting.

"This is the best win of my career," the 18-year-old said. "Today I played my game and beat my favorite player. I admired her as a child."

The 15th-seeded Bammer overcame strong winds to win 6-3, 7-6 (8). Bammer broke Kuznetsova's serve three times in the first set, and both players had four breaks in the second.

"It is always great to beat a top-10 player," Bammer said. "She is a good player with a lot of ability. The conditions were terrible to play. But we have to play in such conditions no matter what."

In earlier matches, Vera Zvonareva beat 11th-seeded Dinara Safina 7-5, 6-3 and Caroline Wozniacki rallied to oust Anabel Medina Garriegues 3-6, 7-6 (7-3), 6-3.

Top-seeded Ana Ivanovic pulled out of the tournament before her third-round match against Agnieszka Radwanska because of a left ankle injury she sustained yesterday.