Wimbledon finalist Vera Zvonareva defeated Slovakian Dominika Cibulkova 6-0, 3-6, 6-4 on Tuesday in her first match at the 700,000-dollar WTA San Diego Open.
It was the first match for the third-seeded Russian since she lost to US star Serena Williams in the Wimbledon championship match.
Zvonareva, ranked ninth, breezed through the first set but was pushed to a third as Cibulkova battled back.
But Zvonareva answered the challenge, showing no sign of a right hamstring injury that saw her withdraw last week at Stanford.
Next up for Zvonareva will be US qualifier Coco Vandeweghe, who advanced when Argentina's Gisela Dulko retired with a sprained right ankle after losing the first nine games.
Polish fourth seed Agnieszka Radwanska defeated South African Chanelle Scheepers 7-5, 6-3 to book a date in the round of 16 against Russian Dinara Safina, who snapped a six-match losing streak on Monday.
China's Zheng Jie defeated American Shenay Perry 6-3, 6-2 while Israeli seventh seed Shahar Peer ousted Serbian Ana Ivanovic 7-6 (7/3), 6-3.
Italian fifth seed Flavia Pennetta downed Ukranian Kateryna Bondarenko 6-2, 7-5 and will next face Russian Maria Kirilenko, who outlasted Japan's Kurumi Nara 6-4, 6-7 (4/7), 6-3.