Top seed Maria Sharapova earned an efficient 6-2, 6-1 victory over Sania Mirza in Carlsbad on Friday to reach the semi-finals of the $1.3 million San Diego Classic.
Sharapova, the defending champion, awaits the winner of Friday night's quarter-final clash between two in-form players - Wimbledon champion Venus Williams and Russian third seed Anna Chakvetadze.
Chakvetadze is seeking a third title in as many weeks after triumphs at Cincinnati and Standford.
Swiss 11th seed Patty Schnyder continued her roll, upsetting Russian fourth seed Nadia Petrova 6-4, 6-4 to reach only her second semi-final of the season. She had stalled seven times at the quarter-final stage this year.
Ninth seed Elena Dementieva moved into her second semi of the season with a 6-2, 6-4 victory over fellow Russian Maria Kirilenko.
Sharapova, playing her first event since a humbling loss to Williams in the Wimbledon fourth round, was pleased with her performance.
"I had a good start and was able to play my game," said the world number two, one of five Russian to reach the quarter-finals during the final edition of this tournament.
"The two keys were serve and return. Sania is a solid player so it's good to get some matches like I've won this week behind my back."
Sharapova lost serve only once, in the second set, but got it straight back on the way to victory in just 61 minutes.
"I've had three good matches, I much prefer it this way than running around for a long time in the hot sun to win," added Sharapova, who is nursing a sore shoulder. "I've got confidence, and I'm ready to step it up in my next match."
Schnyder followed up her three-set win over compatriot Martina Hingis in Thursday's third round with a comprehensive victory against Petrova.
"I made her run a lot and really got my game going well," said Schnyder, who played a third straight quarter-final after Cincinnati and Stanford.
"I'm feeling great on the court, especially these past three days. Everything seems to fit well in my game. I just want to keep this up for the weekend."