Stanford:Third-seeded Daniela Hantuchova, seventh-seeded Katarina Srebotnik, and eighth-seeded Sybille Bammer reached the quarterfinals of the Bank of the West Classic.
Lilia Osterloh rebounded from a tough first set to beat second-seeded Marion Bartoli 5-7,6-4, 6-3 to advance to the quarterfinals.
In her fifth appearance at the event, Osterloh reached the quarters for the second time and the first in six years by beating the Wimbledon finalist.
"It's a really great feeling knowing she beat the world's No 1 and No 3 players," Osterloh said. "It helps my confidence a lot."
Bartoli, who injured her right leg at the French Open, took a medical timeout for a right quad strain during the first set and was never able to move as well again.
"My body was just not ready to play," said Bartoli, who reached her career best ranking after her run at Wimbledon. "I'm showing signs of (exhaustion) and it will take some time to recover. She played a good match and she was just too good at the end."
Osterloh, currently ranked 106th in the world, received a wild card to this event.
The 12th-ranked Hantuchova beat Shuai Peng, 6-4, 6-2; Srebotnik downed Maria Kirilenko 6-0, 7-6 (5); and Bammer, who will play Osterloh, topped Meilen Tu, 6-4, 6-2.
Srebotnik trailed 6-5 in the second set after a series of challenges. Kirilenko hit a backhand lob to win the game but Srebotnik rallied to the tiebreaker.
"I felt I had to lift my game down 6-5 in the second set," Srebotnik said. "Then I was strong early in the tiebreaker. She started to serve very well and made it tough for me on returns. I played well in the first set and did not make many mistakes. In the second set, she adjusted and it was a tough set."
Bammer improved her serve in the second set to eliminate Tu.
"This was a very tough match for me. I have lost to her before in Wimbledon and also in practice sessions," Bammer said. "She was playing very aggressive and I thought she took some risks at times. I have been trying to improve my fitness and play better mentally."