The top two seeds, Venus Williams and Lindsay Davenport, who have both won twice at Stanford, reached the semi-finals of the Bank of the West Classic in contrasting manner on Friday.
Williams destroyed fifth seed Anna Smashnova-Pistolesi 6-0, 6-3 but Davenport had to struggle to overcome lucky loser Mashona Washington 6-4, 3-6, 6-1.
The top seed played a nearly perfect first set, winning 24 out of 28 points in a mere 15 minutes.
Williams blasted huge serves past the bewildered Israeli and dominated the rapid-fire baseline chances without breaking sweat.
She broke Smashnova to open the second set but then the fifth seed began to find her game and challenged Williams with her heavily top-spinned strokes.
But Smashnova could never completely blunt Williams's power or keep her off her back at the net.
"I couldn't miss a ball," Williams said. "I had a lot of pace on my ball and she wasn't used to it. We only played once before on clay (won by Williams) and she's a lot more confident on that surface. I was hitting a whole lot faster tonight."
Williams will meet sixth seed Amy Frazier, who upended third seed Patty Schynder of Switzerland 6-3, 7-6, in the semi-finals.
In reaching her first WTA tier II quarter-final, the 28-year-old Washington played an extremely ambitious match against Davenport, going for broke on her serves and rifling her returns.
But after coming back from a break down in the second set and stunning Davenport, errors began to creep into her game.
After Davenport broke her in a long game to go ahead 2-0 in the third set, Washington mentally fell apart.
"It was important not to get broken early," Washington said. "It boiled down to me not serving as well and her raising her level.
"I forced a few shots, and maybe I could have rallied a little more. Players as good as her force you to make shots you normally don't go for. I didn't hold up my end."
Davenport will now meet eighth seed Maria Vento-Kabchi of Venezuela, a 6-4 6-1 winner over Italy's Francesca Schiavone.
Wimbledon semi-finalist Davenport, who re-injured her knee at the French Open, is now travelling full-time with a trainer, Laura Eby. She believes that her knee can hold up for the next three weeks. She is scheduled to play Los Angeles next week and San Diego the week after that.
"Everything feels fine," she said. "I've done this before and I can do it again."