Peng was joined in the last 16 by Slovenian seventh seed Katarina Srebotnik, the only ranked player in action on the opening day, who recorded a routine 6-3, 6-4 victory over Russia's Olga Poutchkova.

The 21-year-old Peng played corner-to-corner against the taller Bovina, frequently wrong footing her opponent into errors with an intelligent and aggressive game honed by her new coach, former world number two Michael Chang.

"She hits hard, so I tried to hit hard first. She is a big girl, so I tried to move the ball around," said Peng.

At world number 62, Peng is China's second-ranked player and is making a comeback after suffering a serious ankle injury in early May.

Two Americans also advanced after Meilen Tu beat compatriot Meghann Shaughnessy 7-6, 6-1 and Lilia Osterloh defeated Jill Craybas 6-2, 7-5 to earn herself a meeting with second seed and Wimbledon finalist Marion Bartoli of France.

Greece's Eleni Daniilidou outlasted American Amber Liu 4-6, 7-5, 6-1 to set up a second-round showdown against third seed Daniela Hantuchova.

Daniilidou next faces Russian top seed Anna Chakvetadze, who comes into the event on the back of a tournament victory in Cincinnati.