Top-seeded Victoria Azarenka advanced in Monday's third-round action at Indian Wells, but she had to bounce back to down 28th-seeded Kirsten Flipkens, 3-6, 6-3, 6-0 before moving on.
Azarenka, of Belarus, reeled off nine straight games to down Flipkens in one hour, 46 minutes on Monday at the $5.186 million BNP Paribas Open.
Azarenka beat Maria Sharapova in last year's final in the California desert.
Fourth-seeded German Angelique Kerber moved on by dismissing 30th-seeded Belgian Yanina Wickmayer 6-1, 7-6 (7-4), while seventh-seeded former U.S. Open champion Samantha Stosur of Australia held off 32nd-seeded Peng Shuai of China, 6-3, 3-6, 6-2 on the hardcourts at Indian Wells Tennis Garden.
Caroline Wozniacki, who titled here in 2011 and was the runner-up in 2010, defeated 29th-seeded Elena Vesnina 6-2, 6-1.
Tenth-seeded Russian Nadia Petrova eased into the round of 16 with a 6-1, 6-2 pasting of 21st-seeded German Julia Goerges.
Fellow German and 24th-seeded Mona Barthel outlasted 11th-seeded Serbian Ana Ivanovic 6-1, 3-6, 6-0. Ivanovic was the 2008 Indian Wells champ and 2009 runner-up.
In other third-round play, Spaniard Garbine Muguruza dispatched Slovak Magdalena Rybarikova 6-4, 6-0 and Urszula Radwanska eased past American Jamie Hampton, 6-0, 7-6 (7-4).
On Monday morning, a 4.7 magnitude earthquake hit a wide area of Southern California, including Indian Wells. The epicenter was about a dozen miles from the desert town of Anza, about 100 miles from Los Angeles.
This Premier Mandatory WTA event will pay its newest champion $1 million.