In a clash of two former world No. 1-ranked players, Williams put on a clinic with precision serving and a sharp ground game to get the better of the Russian.

Williams’ semifinal opponent will be German Sabine Lisicki, who beat fifth-seeded Agnieszka Radwanska of Poland 7-6 (4), 2-6, 6-2.

Third-seeded Marion Bartoli of France advanced when Japan’s Ayumi Morita retired after dropping the first set 6-1. Bartoli will meet eighth-seeded Dominika Cibulkova of Slovakia, who beat qualifier Marina Erakovic 6-1, 6-1.

Williams, playing in just her third tournament since winning Wimbledon last year, and her first on American soil since the 2009 US Open, looked as good as she did when she topped the rankings.

The fifth-ranked Sharapova had eight unforced errors before she hit her first winner and the slow start proved costly.

“I had a good start,” Williams said. “You can’t go in against the fifth-ranked player with your mind everywhere. You have to be serious. It’s a great win for the hardcourt season.”

“I’m a better player this month than I was last month. I’ve put in a lot of work and I hope it continues to pay off.”

Williams, currently ranked No. 169, beat Sharapova for the sixth straight time and improved to 7-2 overall against her. Sharapova last beat Williams at the 2004 WTA championships.

“It certainly wasn’t my night,” Sharapova said. “She was serving and hitting so well and I was extremely late in my reactions. I felt sluggish. It was a bad day but it’s also a reminder that I need to step up.”

“When I had chances to change things around I couldn’t do it. Her biggest strength is her power and you don’t see so much of that in the top 10. It really makes her dangerous.”

Lisicki was a semifinalist at Wimbledon and has improved her ranking to 26th after being No. 218 in March.

“I’m looking forward to the match,” Lisicki said. “I love competing in the big matches. I have nothing to lose.”

Sharapova beat Lisicki in the semis at Wimbledon.

“Coming from grass to hardcourt is always a challenge,” Lisicki said. “It comes down to who plays the best that given day.”

Last year, Lisicki missed five months with a left ankle injury. She says she has more endurance now than before her injury.

“I’m much better than I was before the injury,” she said. “I’ve had to focus on so many aspects of my game. Last year I couldn’t even walk. Now I feel I can rely on my serve when I need it at crucial moments.”

The 20th-ranked Cibulkova, looking for her first tour title, reached her second semifinal of the year.

“I was pretty solid the whole match,” Cibulkova said. “I hope to keep playing at this level.”