China's Peng Shuai and former world No. 1 Ana Ivanovic both won in straight sets on Wednesday in the second round at the Mercury Insurance Open, while Germany's Julia Goerges made an unexpected early exit.

Peng won 6-1, 6-3 against Australia's Anastasia Rodionova to set up a clash with Italy's Sara Errani. Serbia's Ivanovic beat Japan's Ayumi Morita 6-1, 7-6 (5), avenging a first-round, straight sets loss last week and setting up a match against another Italian, Alberta Brianti.

The shock of the day was provided by American teenager Sloane Stephens, who had an upset 6-3, 7-5 win over seventh-seeded Goerges despite a potentially costly and embarrassing mistake.

Stephens beat her German opponent with a steady ground game and won despite squandering a set point when she allowed a ball that was going out to hit her in the back.

"Today wasn't her best day. I'm happy I got her on this day," the 18-year-old Stephens said. "But everyone has their days and today wasn't hers. I guess it was mine."

No. 11 seed Maria Kirilenko of Russia withdrew from the tournament with a left hip injury before her second-round match against Romania's Tamira Paszek. Stephens will face Paszek in the next round.

Sabine Lisicki, the No. 12 seed from Germany, overwhelmed 40-year-old Kimiko Date-Krumm of Japan 6-1, 6-2. Lisicki's next opponent will be local favorite, 19-year-old Coco Vandeweghe, who was a 6-7 (5), 6-4, 6-3 winner over lucky loser Olga Savchuk of the Ukraine.

"I always have really tough matches against Kimiko," Lisicki said. "I think I controlled the point from the start with the serve and the return. I took her weapon away a little bit."

Ivanovic, after winning the first set easily, lost the first five games of the second set before reeling off five consecutive games herself and forcing the tiebreaker. Her next opponent Brianti also had a topsy-turvy match, failing to win a game in the first set before edging Sweden's Sofia Arvidsson 0-6, 7-6 (5), 7-6 (7).

Eighth-seeded Daniela Hantuchova of Slovakia won her first match 6-1, 6-3 over Barbara Zahlavova Strycova of the Czech Republic to set up a meeting with Zheng Jie of China, who upset No. 9 seed Roberta Vinci of Italy, 6-4, 6-2.

No. 16-seeded Polona Hercog of Slovenia lost 4-6, 6-1, 6-4 to Russia's Vera Dushevina, whose next challenge will be top-seeded Vera Zvonareva.

In Washington, Wayne Odesnik played his first ATP main-draw match on Wednesday since returning from suspension, and lost. About 18 months ago Australian customs officers caught him with eight vials of human growth hormone.

The American was beaten 1-6, 1-6 by Radek Stepanek of the Czech Republic at the Legg Mason Tennis Classic. Odesnik held serve in the opening game, then, after a rain delay of nearly two hours, dropped the next 11 games in a row at the hardcourt tuneup for the US Open.

"I'm just trying to move on with my career, with my life, put it behind me the best that I can, and that's it," Odesnik said. "If they have negative things to say, that's them. I'm not going to sit here and bad-mouth anyone. ... They don't matter to me."

Odesnik said the past 18 months "rejuvenated my career, because I'm a lot hungrier."

There was better news for two other Americans: Donald Young progressed to the round-of-16 after opponent Jurgen Melzer retired in the midst of a third-set rain delay with a pulled leg muscle while trailing 6-4, 3-1; and Michael Russell also profited from an opponent's injury when Xavier Malisse quit with an arm injury while trailing 7-6 (4), 2-3. In the only other match that was completed before showers interrupted play again and led to the postponement of six singles matches, No. 9 Nikolay Davydenko beat Matthew Ebden of Australia 6-3, 7-5.