Second seed Venus must wait another year for her first title here after Russian 19th seed Nadia Petrova showed a steely resolve and a superior ability to cope with the swirling, chilly conditions that dogged day eight of the claycourt slam.

The women's event has been shaping up for another Williams sisters final, but Petrova outclassed Venus, who opted for a more modest version of the black lacy corset that has set Parisian tongues wagging all week.

"It's my most dramatic French Open," said Petrova after booking a place in the last eight against fellow Russian Elena Dementieva with the 6-4, 6-3 triumph.

Earlier, Justine Henin cemented her place in the fourth round after coming through a one-set shootout with another former world number one, Russian 12th seed Maria Sharapova.

The four-time champion trailed 0-2, 0-40 in the decider after darkness had halted their third-round match on Saturday at one-set all, but a change of gear from the Belgian saw her to a 6-2, 3-6, 6-3 win and meant Sharapova is still missing only the French Open title from her Grand Slam collection.

Federer may be one of Stanislas Wawrinka's closest friends on the tour but it did not stop the defending champion from driving his fellow Swiss mad with frustration as he nonchalantly booked his place in the quarterfinals.

Wawrinka had the audacity to break the Federer serve in the second set and had the upper hand until the man he won Olympic doubles gold in 2008  decided to turn the screw.

He took the second set to a tiebreak which he won 7-5, prompting Wawrinka to smash his racket into the red clay three times, mangling the frame and strings in the process.
The resulting code violation failed to galvanise him and Federer stormed through the third set to record a 6-3, 7-6, 6-2 victory in under two hours.

Federer now faces Robin Soderling, the man he beat to complete his career Grand Slam here last year, after the dangrous Swede destroyed Croatia's Marin Cilic 6-4, 6-4, 6-2.
French hopes died when Jo-Wilfried Tsonga retired injured after losing the first set against Mikhail Youzhny.

Dementieva ended the dream run of qualifier Chanelle Scheepers, winning 6-1, 6-3 in an error-strewn opener on Court Philippe Chatrier.

Italian veteran Francesca Schiavone reached the quarterfinals for the first time since her maiden appearance in 2001 after a defiant 6-4, 6-4 over Russian 30th seed Maria Kirilenko.

World number three Caroline Wozniacki came out on top in a three-hour tussle to down Italian Flavia Pennetta 7-6 , 6-7, 6-2 in her fourth round match.

Results (prefix denotes seeding): Men, fourth round: 11-Mikhail Youzhny (Rus) bt 8-Jo-Wilfried Tsonga (Fra) 6-2 (retd); 5-Robin Soderling (Swe) bt 10-Marin Cilic (Cro) 6-4, 6-4, 6-2; 1-Roger Federer (Sui) bt 20-Stanislas Wawrinka (Sui) 6-3, 7-6 (7-5), 6-2.
Women, fourth round: 3-Caroline Wozniacki (Den) bt 14-Flavia Pennetta (Ita) 7-6 (7-5), 6-7 (4-7), 6-2; 19-Nadia Petrova (Rus) bt 2-Venus Williams (US) 6-4, 6-3; 17-Francesca Schiavone (Ita) bt 30-Maria Kirilenko (Rus) 6-4, 6-4; 5-Elena Dementieva (Rus) bt Chanelle Scheepers (SA) 6-1, 6-3. Third round: 22-Justine Henin (Bel) bt 12-Maria Sharapova (Rus) 6-2, 3-6, 6-3.