DALLAS, TX, USA - More qualifiers than seeds remain at the upset-filled Texas Tennis Open, with No.2 seed Dominika Cibulkova the latest victim.

The last time they played, Cibulkova edged Kateryna Bondarenko in a third-set tie-break in the second round of last year's US Open and ended up going all the way to the quarterfinals. Almost a year later, it was a much different story, with Bondarenko converting on six of seven break point opportunities en route to a 63 61 victory on Wednesday that took just over an hour. Bondarenko, a qualifier this week, is into her fifth quarterfinal of the year, having gone 1-3 in the previous four, and will have fifth-seeded Sabine Lisicki standing in her way of her second semifinal of 2011.

Two other qualifiers also won in straight sets, with Angelique Kerber defeating Melanie Oudin, 63 62, and Aravane Rezai beating Sorana Cirstea, 62 76(4). Kerber started the first set in a 1-3 hole but only lost two more games the rest of the way. Her next match against Johanna Larsson will be her first quarterfinal since Hobart in January. Rezai reached her only previous quarterfinal of the season in Baku last month. She will take on Elena Baltacha, whom she has lost two in both of their encounters this year.

Also Wednesday, Anastasija Sevastova topped Sofia Arvidsson, 76(4) 64, to advance to her first quarterfinal since Monterrey in March.

"I switched gears in the second set when I was 4-2 down, started to play more aggressively, make less mistakes, and then I won the next four games in about 10 minutes," said Sevastova, who only lost three points in the last four games and will play No.8 seed Irina-Camelia Begu in Thursday's quarterfinals.