Pale and shaky, Marion Bartoli kneeled near the service line and grabbed her stomach.

The 25-year-old Frenchwoman was sending the international signal for "I don't feel so good."

Bartoli, ranked 12th in the world in women's tennis and seeded fifth at the Family Circle Cup, was forced to retire two hours and 34 minutes into her second-round match on Stadium Court Wednesday night, falling victim to a bout of dizziness.

China's Shuai Peng led in the third set by 2-6, 7-6 (2), 4-3 when Bartoli called it quits, the second seeded player forced to retire Wednesday. No. 3 seed Victoria Azarenka bowed out earlier in the day with a hamstring injury.

Peng, ranked No. 58, advances to play No. 33 Elena Vesnina in the third round.

Bartoli showed no sign of trouble early in the match, taking control of the first set in an epic fifth game, finally cashing in on her fifth break point and winning four straight games to take the set in 45 minutes.

But Peng, who like Bartoli slugs with two hands on both wings, bounced back to win the first three games of the second set en route to a 4-1 lead.

Bartoli battled back, breaking serve in the seventh game and climbing all the way back to 6-6 to force a tiebreak.

But the effort took its toll.

Bartoli's fifth double fault helped Peng take the tiebreak by 7-2, forcing the third set that Bartoli never made it through.

The players traded breaks in the fourth and fifth games, Bartoli holding a 3-2 lead when she called for a trainer on the changeover, 2:18 into the match.

Bartoli, her long-sleeved shirt soaked with sweat on a chilly night, complained of dizziness, and the trainers checked her blood pressure and heart rate, wrapping a towel around her shoulders.

After a delay of a few minutes, Bartoli resumed play, but she looked pale and had to pause several times, holding her midsection. After two more games, both won by Peng for a 4-3 lead, Bartoli called for the trainer again, and this time decided she could not go on.

Peng walked over to shake hands and to check on Bartoli, who was able to leave the court under her own power.

It was a disappointing result for Bartoli, who lost in the semifinals last year to eventual champion Sabine Lisicki. Bartoli was coming off a great performance in Miami, where she lost to Venus Williams in the semifinals.

Bartoli flew from Miami to Charleston last week to spend a week practicing on clay before the Family Circle Cup.

"The first hit was pretty good considering I hadn't stepped on a clay court for a whole year," Bartoli wrote on her blog for the Sony Ericsson WTA Tour. "It's safe to say this isn't my best surface. I'm not sure how the tournament will go, but I'm happy with my level right now and I'm improving all the time."

Peng, 24, lost in the third round to Caroline Wozniacki in last year's Family Circle Cup. She can better that result this year with a win over Vesnina, a 7-5, 6-2 victor over Sofia Arvidsson.