Roger Federer and Andre Agassi stayed on course for a quarter-final showdown at the U.S. Open on Saturday, but Maria Sharapova and Carlos Moya were heading home after shock third-round exits.

As the year's final Grand Slam began to heat up women's top seed Justine Henin-Hardenne also advanced to the fourth round where she was joined by in-form Lindsay Davenport who notched her 20th consecutive victory.

World number one Federer oozed class against unorthodox Frenchman Fabrice Santoro, winning 6-0, 6-4, 7-6 to move closer to becoming the first man to win three major titles in the same year since Mats Wilander in 1988.

After a blip in the previous round against Cypriot qualifier Marcos Baghdatis, Federer was back to his flowing best to reach the last 16 where he will face Romanian Andrei Pavel.

"Today I was feeling good, my forehand was working and my serve was there when I needed it," said Federer, who is looking for revenge over Agassi after he was thrashed by the American in the fourth round in 2001.

"It's still a match away from it but it would be nice to play him here, at the Open, to get my revenge because he got me badly the last time," added Federer, who has never been beyond the fourth round.

Agassi, the oldest man in the draw at 34, demolished Czech Jiri Novak 6-4, 6-2, 6-3 to reach the fourth round for the 14th time of his extraordinary career.

The sixth seed dished out a 92-minute lesson to Novak, who had no answer to the sixth seed's laser-guided groundstrokes.

"I turned a corner I needed to turn going into the second week," Agassi said. "To beat a player like Novak in straight sets is a very good match for me.

"I felt I executed the meat and potatoes well today."

SHARAPOVA DUMPED

The Sharapova bandwagon was brought to a juddering halt on Arthur Ashe as Mary Pierce rolled back the years with a sensational 4-6, 6-2, 6-3 victory.

The 17-year-old Wimbledon champion was expected to overpower the former French and Australian Open winner but Pierce had clearly not read the script.

Sharapova won the first set convincingly but 29-year-old Pierce launched a devastating fightback to go through.

Sharapova, who wore a black ribbon in memory of the tragic events at Beslan where Chechen gunmen killed more than 320 people, tried to keep it all in perspective.

"It's not the end of the world, I only lost a tennis match and there are far more important things going on in the world."

Another Russian did progress, however, Nadia Petrova coming through a three-hour marathon against Silvia Farina Elia to set up a fourth-round meeting with top seed Henin-Hardenne.

The Belgian, still struggling from the after-effects of a debilitating virus which kept her off the tour for 12 weeks, battled to a 6-4, 6-3 victory over gritty American Lisa Raymond.

"Little by little I think my game is improving," said Henin-Hardenne, who arrived at Flushing Meadows tired after winning Olympic gold in Athens. "Mentally I was feeling stronger today than I have done for the last few days."

BELGIAN DELIGHT

Olivier Rochus, who had never won a singles match at the U.S. Open before this year, completed a great day for Belgium when he hustled his way past third seed Moya.

Rochus, the smallest man in the draw, was inspired as he withstood all Moya could throw at him to claim a 4-6, 6-4, 6-3, 6-7, 7-5 victory in three hours 38 minutes.

"That was the best match ever," he said. "The atmosphere was phenomenal for me. Everything, my game, the crowd. I think I will never forget this match, that's for sure".

In an eventful night session, Davenport survived a set point against Russian Elena Bovina to win 7-6, 6-2 and set up a mouth-watering last 16 match-up with Venus Williams.

Williams was far from her best against fellow American Chanda Rubin, but did just enough for a 7-6, 6-3 victory.

"It's a tough draw for sure," Davenport said of her impending clash with Williams.

"Not what you would want really in the last 16."

Two men's five setters had fans on the edge of their seats.

Armenian Sargis Sargsian followed up his five-hour marathon against Nicolas Massu with another epic against Paul-Henri Mathieu, saving two match points to win 4-6, 4-6, 6-4, 6-2, 7-6 in fours hours 41 minutes to take his total court time to more than 12 hours. His reward is fourth round against Agassi.

Fifth seed Tim Henman twice trailed by a set but kept his Open dream alive with a 4-6, 6-3, 5-7, 6-4, 6-3 defeat of Czech qualifier Michal Tabara to reach the fourth round where he will play Germany's Nicolas Kiefer.

The last surviving qualifier in the women's draw fell when 17-year-old Anna Chakvetadze, who beat fellow Russian and French Open champion Anastasia Myskina in the previous round, lost to Greece's Eleni Daniilidou 6-4, 6-2.