NEW YORK — Roger Federer looked every bit a champion and stayed perfect at this U.S. Open. Andy Roddick showed shades of winning form, too.

No longer No. 1, Federer beat Radek Stepanek 6-3, 6-3, 6-2 today and breezed into the round of 16.

To win his first Grand Slam of the season, Federer needs to take his fifth straight title at Flushing Meadows. He has not lost a set in three matches, and raised his right fist after zinging a final, winning forehand down the line.

"I guess it's just nice to play well. Pretty simple," the No. 2 Federer said. "No complaints."

Roddick, the last man to win the Open before Federer, beat No. 31 Andreas Seppi 6-2, 7-5, 7-6 (4).

The eighth-seeded Roddick usually relies on his power serve. Down in the tiebreaker, he smartly served from the shadows into the bright sun, launching a wide, 126 mph ace that blinded Seppi.

"This is probably the most intimidating court in the world if you've never been on it before," Roddick said.

Stepanek is among nine players to beat Federer this season, sweeping a pair of tiebreakers at Rome in May. But at 29 years old and seeded 28th, the oldest player left in the men's draw was no match for a player who seems to be on a mission.

Federer got broken for the only time in the first set, then broke back at love and held to win. In the third set, he double-faulted twice before winning his final 11 points on serve.

Federer won a gold medal in doubles at the Olympics, but lost in singles.

"It was one of my goals coming into this season, next to trying to win Wimbledon. I missed that one. Oh, well," he said, drawing laughs from crowd.