Top seed Venus Williams gained revenge over Meghann Shaughnessy with an easy 6-4 6-1 win to move into the quarter-finals of the Bank of the West Classic.
Williams will play the resurgent Russian Anna Kournikova, who won back-to-back matches for the first time since mid-May, defeating Indonesia's Wynne Prakusya 7-5 6-4.
American veteran Lisa Raymond also triumphed, defeating Marissa Irvin 6-1 6-4 and she now meets third seed Monica Seles for a place in the last four.
In the day's other late match, Yugoslavian teenage wildcard Jelena Jankovic stunned seventh-seeded Daja Bedanova 7-6 2-6 6-3 to set up a quarter-final against defending champion Kim Clijsters.
Playing in her first match since falling to her sister Serena in the Wimbledon final, Williams served efficiently and with great variety, outfoxing Shaughnessy in crosscourt rallies and eating up her opponent's second serve.
Last year, Shaughnessy shocked Williams in a three sets but this time the top seed set up her victory by winning nine straight games after falling 4-2 behind. "When I finally settled shown, I felt very confident from the baseline," she said.
"This year, I was a more prepared. Last year, I was too settled and didn't practice before I came here. Sometimes when you think you are at your strongest, you are at a your weakest."
A disappointed Shaughnessy said she failed to raise her game when Williams stepped up the pace. "Because I had beaten her before I thought, 'Why not again?', but to do that I'd have to put together better tennis than I did," Shaughnessy said.
Kournikova is 0-7 against Williams, including two losses here in 1999 and 2000 and two earlier this season in Antwerp and Dubai.
"She's playing amazing tennis, but I have nothing to lose so I'll go out and try to stay on the court as long as I can," Kournikova said.
"It's really difficult to come in against any player who hits the ball as fast and as deep as Venus. I'm going to have to be creative and try to open the court up."
Williams doesn't expect an easy contest. "I have a lot of respect for her as an athlete more than anything," Williams said. "She moves well and improvises but has had her fair share of bad luck.
"Hopefully, I'll maintain my good record against her."
