PARIS (AFP) Top seed Serena Williams survived a French Open health scare on Saturday, while Russias Nadia Petrova defeated Roland Garros golden girl Aravane Rezai in a marathon, centre court comedy of errors. Williams, the 2002 champion, beat Russias 29th seed Anastasia Pavlyuchenkova 6-1, 1-6, 6-2 to reach the last 16, but needed treatment after slipping at 0-5 down in the second set, having cruised through the opener. She had her pulse tested and temperature taken courtside, although she did manage to compose herself to win the next game before the 18-year-old Russian went on to level the match. Williams, despite still appearing uncomfortable, then broke twice in the final set and will face either Israels Shahar Peer or Marion Bartoli of France for a place in the quarter-finals. Williams, who won a 12th career Grand Slam singles title in Australia in January, arrived in Paris under an injury cloud after a knee injury sidelined her until May. Serenas a great fighter, said Pavlyuchenkova, a former junior world champion. In the third set she was still confident. She is Serena. Maybe she took some pain-killers from the doctor, she could have been a little dizzy. But she was still aggressive and played with more power. Petrova, the Russian 20th seed, beat French 19th seed Rezai 6-7 (2/7), 6-4, 10-8 in a third-round match that had been suspended in darkness on Friday at 7-7 in the final set. Petrova had already squandered three match points, but in a final set that contained 11 service breaks, the two-time semi-finalist held her nerve and will tackle second seed Venus Williams for a place in the quarter-finals. The 2hr 48min encounter featured 46 unforced errors by Rezai and 40 off the Russians side with the French girl carving out 23 break points to Petrovas 15. Australias Slovakian-born Jarmila Groth defeated Russian-born compatriot Anastasia Rodionova 6-3, 5-7, 6-2 to reach the last 16 of a Grand Slam for the first time. The 23-year-old wildcard, who was granted Australian citizenship in November 2009, will face either Russian 28th seed Alisa Kleybanova or Yaroslava Shvedova for a quarter-final place. Later on Saturday, four-time champion Justine Henin takes on fellow former world number one Maria Sharapova in a marquee match-up. The pair have met nine times, with the Belgian leading their series 6-3, including a straight sets victory over the Russian in the quarter-finals here in 2005. Sharapova won their last meeting at the Australian Open quarter-finals in 2008. Serena survives health scare to reach last 16 Top seed Serena Williams survived a worrying mid-match health scare to defeat Russias 29th seed Anastasia Pavlyuchenkova 6-1, 1-6, 6-2 and reach the French Open last 16 on Saturday. The American world number one, who was the 2002 champion here, required treatment courtside after slipping at 0-5 down in the second set, having cruised through the opener. She had her pulse tested and temperature taken although she did manage to compose herself to win the next game before the 18-year-old Russian went on to level the match. Williams, still appearing uncomfortable on court, fought off three break points in the third game of the decider. Pavlyuchenkova, bidding to reach the fourth round of a Grand Slam for the first time, was then immediately broken as Williams unleashed a barrage of heavy forehands to shorten the points as well as her time on court. The American broke again in the eighth game to take the tie and will face either Israels Shahar Peer or Marion Bartoli of France for a place in the quarter-finals. Williams, who won a 12th career Grand Slam singles title in Australia in January, arrived in Paris under an injury cloud after a knee injury sidelined her until May.