New York - Former champions Roger Federer and Andy Roddick turned in impressive straight-set wins, throwing down a challenge to rivals as they powered through into the second week of the US Open on Sunday.

Four-time winner Federer took a step closer to lifting his first major title of a subdued season as he turned in a near-flawless performance to crush Radek Stepanek 6-3, 6-3, 6-2.

Rodick, the 2003 champion at his home Grand Slam, rolled Italian Andreas Seppi 6-2, 7-5, 7-6 (7-4).

"I feel good," said the 26-year-old. "It's just a matter of getting into physical and mental shape. I'm excited, I cannot wait for the fourth round."

Roddick had his way in "the most intimidating court in the world" against the number 31 who has stalled in the third round at Slams.

Federer, seeded second behind French Open, Wimbledon and Olympic champion Rafael Nadal, is bidding for his fifth straight trophy at Flushing Meadows.

The Swiss earned revenge after losing to Stepanek in straight sets in Rome last May. "That loss hurt, but it's a good win for me. I'm moving on, and that's what I care about right now."

Federer's efficient New York victory quieted the annoying, strutting style of the Czech number 30, still never past the third round at the event.

"It's good for me to not waste any energy," said the 12-time winner of major singles titles. "I'm playing well and moving on in the draw. At the end of the day, what counts is winning the tournament."

Federer's comprehensive victory was his 30th straight at the Open, his last loss coming to David Nalbandian in 2003.

Federer squares off against Russian Igor Andreev who put out Spanish 13th seed Fernando Verdasco 6-2, 6-4, 6-4.

Russian fifth seed Nikolay Davydenko, a semi-final loser to Federer at the last two editions, advanced into the fourth round over fellow Russian Dmitry Tursunov 6-2, 7-6 (7-3), 6-3.

Former junior champion Gilles Muller took well over three hours to complete a marathon victory against Spain's Nicolas Almagro 6-7 (3- 7), 3-6, 7-6 (7-5), 7-6 (8-6), 7-5.

On the women's side, Jelena Jankovic continued her bid to wrest the number one ranking from compatriot Ana Ivanovic, reaching the second week over Dane Caroline Wozniacki 3-6, 6-2, 6-1.

Jankovic has her chance to return to the position she held in early August before Ivanovic - a second-round upset victim as top seed - took it from her prior to the start of the season's last Grand Slam.

"Little by little every day I feel that I'm getting better and better," said the Serb. "Physically I'm moving much better. My condition is getting better and better."

Jankovic had to rally past the teenaged challenger for the second time in as many meetings, both coming at majors.

At Wimbledon, Wozniacki got off to a fast start before begin pegged back by the 23-year-old seed.

"In the first set she played quite solid, putting all these balls back. She didn't make any errors, I was the one who was all over the place," Jankovic said.

She plays in the quarter-finals against Sybille Bammer, who beat former Wimbledon finalist Marion Bartoli 7-6 (7-3), 0-6, 6-4.