Maria Sharapova [Images] led a trio of Russians into the last 16 of the French Open on Saturday while a relieved fifth seed David Ferrer was given an unnerving reminder of just how effective Lleyton Hewitt's [Images] grit can be.

Top seed Sharapova, so unconvincing in her first two matches this week, looked like she was in for another slog when it took her 81 minutes to clinch the first set on a tiebreak against 32nd seed Karin Knapp.

But Italian Knapp could not emulate the giantkilling feats of compatriot Flavia Pennetta, conqueror of Venus Williams [Images] late on Friday, by collapsing 7-6 6-0 on Court Philippe Chatrier.

"I kind of forgot what it felt like to finish it in two," said Sharapova, a semi-finalist last year.

"I just have to go out there and try to improve and try to get better, and then when it counts you hope that you're the one that steps up."

Dinara Safina, Sharapova's next opponent, stepped up to the plate to extinguish Asia's faint hopes of a champion with a 6-2 7-5 triumph over China Zheng Jie.

PALE IMITATION

A third Russian, Svetlana Kuznetsova, the 2006 runner-up, bulldozed her way past Nadia Petrova, the 25th seed who looked a pale imitation of the player that twice reached the last four here.

Petrova, semi-finalist in 2003 and 2005 and a former world number three, opened the match with a double fault and it barely got any better for the 25-year-old, losing 6-2 6-1 in just 69 minutes.

"Definitely I think I have a chance. Why not?" former U.S. Open champion Kuznetsova told reporters.

"I think there is a few players who have a really good shot to win it, and I hope one of them is me."

The fourth seed now faces Belarus teenager Victoria Azarenka, who continued her quiet but no less devastating dash through the draw.

Azarenka, without a win in two previous visits to Roland Garros, has lost just six games in reaching the fourth round with a 6-1 6-1 win over Italy's [Images] 18th seed Francesca Schiavone.

Third seed Jelena Jankovic needed three games to complete victory in her third-round match against Slovakia's Dominika Cibulkova, halted in fading light on Friday night. Her 7-5 6-3 win means she now faces 14th-seeded Pole Agnieszka Radwanska.

HEWITT DOGFIGHT

Ferrer reached the last 16 for a second time after a bruising three hour 35 minute dogfight with former world number one Hewitt.

The tenacious Australian came into the tournament with no sort of form behind him and a nagging hip injury curtailing his preparations.

But he outslugged Ferrer for large parts of their encounter before finally succumbing 6-2 3-6 3-6 6-3 6-4 on Court Suzanne Lenglen.

Robby Ginepri was busy dispelling the notion that the chances of an American winner went with the exit of the Williams sisters on Friday.

Ginepri, the world number 88, became the first man from the U.S. to reach the last 16 since Andre Agassi [Images] in 2003 when he dispatched France's [Images] Florent Serra 6-4 6-4 6-4.

Chilean dasher Fernando Gonzalez, the 24th seed, came back from the brink to end the hopes of Rome finalist and Swiss ninth seed Stanislas Wawrinka 5-7 2-6 6-4 6-4 6-4.

Switzerland's [Images] number one, Roger Federer [Images], faces Croatia's Mario Ancic for a place in the last four later on Saturday.

(Editing by Pritha Sarkar)

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