The 20-year-old Safina will face fellow Russian Svetlana Kuznetsova for a place in the semifinals after mounting a stirring comeback to defeat the poster girl of women's tennis.

Sharapova let a 5-1 final set lead slip against her gutsy opponent who had also trailed 5-3 in the first set before staging her first fightback of the fourth round tie.

"It's unbelievable what I did," said Safina, who has reached her first Grand Slam quarterfinal.

"I took things into my own hands. She was dictating and making me run from corner to corner. So I said: 'Okay, now I will try to make her run. I started to look for the lines and I was more aggressive on every point."

Sharapova, who has never got beyond the last eight here, had been far from her best at the French Open having to save three match points before beating America's Mashona Washington in the first round.

"She had nothing to lose at 1-5," said Sharapova.

"The game at 5-2 opened up the door a little bit for her and you get hit in the head. I haven't had those kind of tough matches in the past few weeks."

Meanwhile, Roger Federer produced a clinical 6-3, 6-2, 6-3 victory over Czech Tomas Berdych to stride into the quarterfinals of the French Open on Sunday.

Berdych had entered the contest without dropping a set in this year's tournament but that statistic lasted only 39 minutes against the world's best player.

An outstretched Berdych scooped the ball into the net to drop his serve in the fourth game of the match and Federer maintained the advantage to win the first set.

With grey clouds hovering over centre court, the top seed conjured up a delightful lob that fell millimetres inside the baseline to break Berdych again for a 3-2 lead in the second set.

A wild backhand from the Czech gave Federer the second set and despite dropping his serve for the first time in the contest in the opening game of the third, the Swiss rallied to seal the match when Berdych struck a forehand error.

Federer will next meet Croatian 12th seed Mario Ancic.