Top seeded Victoria Azarenka defeated Urszula Radwanska in straight sets, 6-1, 6-2, to advance to the semifinals at the $795,000 Southern California Open.
Azarenka won seven of 10 break points to defeat Radwanska on the hardcourts at La Costa Resort and Spa and move into her sixth semifinal appearance of the year.
She will face seven seed Ana Ivanovic moved into the semifinals, taking down Roberta Vinci 6-1, 6-7 (1-7), 6-2.
Earlier in the day, French journeywoman Virginie Razzano stunned third-seeded former Wimbledon champ Petra Kvitova 6-7 (6-8), 7-5, 7-6 (10-8) in a marathon 3- hour, 35-minute affair.
Razzano is no stranger to knocking off better-known talent. She also shocked Serena Williams in the opening round at last year's French Open.
Her semifinal opponent will be fifth-seeded Samantha Stosur, who bumped off two seed Agnieszka Radwanska 7-5, 2-6, 6-3 in a 2-hour, 31-minute match. Radwanska, who was the runner-up in Stanford last week, titled here two years ago and was the Carlsbad runner-up in 2010.
The 2013 Carlsbad titlist will claim $125,000.