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.

"It's just a good way to start," Peng told reporters.

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

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.

"I'm feeling much better," she said.

"I'm trying to learn what my real game is and Michael is helping me with that. He was a real fighter and I would like to be like that, too."

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.

After a sloppy first set, Daniilidou regained her stride and overpowered Liu, a wildcard entry, who once won the collegiate championship while playing for Stanford University.

"She's got a little bit tired," Daniilidou said. "I had a hard time seeing at first and then played a lot better and more aggressive in the last two sets."

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

"She's really quick and really improved," Daniilidou said of her next opponent.

"There should be a lot of tension out there and l have to raise my level."