Fourth-seeded David Ferrer became the first top-10 seed to fall in the men's draw of the U.S. Open, losing to Gilles Simon 6-3, 3-6, 6-1, 6-3 in the third round Sunday.

Simon, seeded 26th, confounded Ferrer with a variety of shots that kept him out of sync. Ferrer piled up an uncharacteristic 52 unforced errors, nearly twice as many as Simon.

The skinny Frenchman said he was relaxed on a hot, humid, sunny day in Louis Armstrong Stadium, noting that Ferrer had dominated their previous matchups 5-1 and not many of them were close.

"He destroyed me every time, so I felt I had nothing to lose," Simon said. "I just wanted to go out and enjoy myself on the court."

Roger Federer, meanwhile, regrouped after a fortuitously timed rain delay to avoid an upset.

The second-seeded Federer was a game from losing the first set to Marcel Granollers in the third round Sunday when play was stopped because of lightning. After they returned to the court two hours later, Granollers won the set but Federer dominated the rest of the way in a 4-6, 6-1, 6-1, 6-1 victory.

Drenched with sweat on a humid night, Federer acknowledged afterward that the break helped him. He started serving better in the final three sets.

"He was doing a lot of things really well," Federer said later. "It was just, for me, going to be one of those things to like weather the storm and see if he could maintain that level of play or not and if I could lift my game up and see how that matched up. I think overall it worked out great at the end."

The 42nd-ranked Granollers was looking to make the fourth round at the U.S. Open for the second straight year.

Federer next faces 17th-seeded Roberto Bautista Agut of Spain, who beat Adrian Mannarino 7-5, 6-2, 6-3. The 17-time Grand Slam champion has dropped one set through three matches.

"I feel very explosive, quick," Federer said.

Going into Sunday, none of the top 10 men's seeds had lost. For Ferrer, it marks his second straight early exit from a Grand Slam tournament after a second-round loss to Andrey Kuznetsov at Wimbledon. That ended the Spaniard's streak of 10 straight major tournament quarterfinals.

Simon moves on to play 14th-seeded Marin Cilic, a 6-3, 3-6, 6-3, 6-4 winner over 18th-seeded Kevin Anderson, for a shot at the quarterfinals. That would match Simon's deepest Grand Slam run, at the Australian Open in 2009.

Sixth-seeded Tomas Berdych and No. 7 Grigor Dimitrov also advanced.