Roger Federer of Switzerland returns a ball to Andreas Beck of Germany during the men's second third round match at the U.S. Open tennis tournament in New York, the United States, on Sept. 2, 2010. Federer won 3-0. [Xinhua/Shen Hong]

Top seed Rafael Nadal advanced to the fourth round of the U.S. Open, while Venus Williams and Kim Clijsters moved into the quarterfinals in the women's singles on Sunday.

Fourth seeded Andy Murray suffered the biggest upset of US Open so far as the British number one was edged out of the US Open by Swiss Stanislas Wawrinka in an epic four-set clash, scoring 7-6 (7-3), 6-7 (4-7), 3-6, 3-6.

Nadal moved one step closer to winning the only Grand Slam tennis title that has eluded him with a 6-4, 6-4, 6-2 win over Gilles Simon of France.

Nadal, who has won all 46 of his service games so far, next will face 23rd-seeded Feliciano Lopez. They are among five seeded Spaniards in the fourth round.

Number 8 Fernando Verdasco and number 10 David Ferrer also won on Sunday. Also advanced into next round was Sam Querrey, a 20th-seeded American who won 6-3, 6-4, 6-4 against 14th-seeded Spaniard Nicolas Almagro.

Two-time U.S. Open winner Williams and defending champion Clijsters reached the last eight in very different fashions.

Williams needed one hour, 54 minutes to overcome her own serving problems and Israel's Shahar Peer 7-6 (7-3), 6-3. The American missed 52 percent of her first serves, struggling with the ball toss in the swirling wind.

Third-seeded Williams lost her serve twice in the first set against the 16th-seeded Peer and wasted six set points. She also had her serve broken once in the second set by Peer.

Clijsters won nine of the final 10 games in a 6-2, 6-1 defeat of Ana Ivanovic that took 59 minutes. Clijsters said it took a few games to adapt to the wind.

Clijsters has won 18 straight matches at the U.S. Open since losing the final to fellow Belgian Justine Henin in 2003. Clijsters didn't play in 2004, won the title in 2005 and didn't play again until returning from retirement to win again last year as an unseeded player.

"In the beginning you just have to settle with the wind, you have to adjust," the second-seeded Belgian said. "I started moving forward better and started dictating the points."

Ivanovic, a 22-year-old Serb who was number1 in the world in 2008 and has dropped to number 40 now, struggled with the 16 mph (26 kph) wind.

Sixth-seeded Italian Francesca Schiavone also reached the quarterfinals as a 6-3, 6-0 winner against 20th-seeded Russian Anastasia Pavlyuchenkova. She will play Williams in the quarters.