Also in California, Kim Clijsterscrushed Ai Sugiyama of Japan 6-1, 6-2 for a quarter-final berth at the Stanford Classic. The top seed and defending champion, Lindsay Davenport, had to pull out of her second round game against Germany's Anna-Lena Groenefeld when a lower back strain forced her to retire while trailing 5-0.
Playing her first match since losing to Davenport in the last eight at Wimbledon, Clijsters ran Sugiyama from side-to-side with pinpoint accuracy until her 30-year-old opponent wilted through exhaustion.
The Belgian successfully attacked Sugiyama's second serve, pushing the Japanese player further back on the court with booming groundstrokes.
"I let her dictate too much in previous matches," said Clijsters. "If I was going to win, I'd have to hit the ball deep and hard."
Clijsters, who won the titles at Indian Wells and Miami earlier this year, has compiled a 13-match winning streak on US hard courts and she clearly revels on the surface.
"From the day I came to America, it just clicked," Clijsters said. "I'm moving well and can take that extra step. When I can take that extra step, I can hit the ball clean."