New York:Roger Federer rallied from a set down to down Spaniard Feliciano Lopez 3-6, 6-4, 6-1, 6-4 Monday and reach the US Open quarterfinals.
Top ranked Federer lost the first set to the left-handed Lopez, barely won the second, then trailed love-40 to start the third before going on to win the next 35 points he served.
Answering every question Lopez posed with an exclamation point, Federer took control of the third set and the match.
Next up for Federer, bidding to become the first man to win four consecutive U.S. Open titles since the 1920s: a quarterfinal against No. 5 Andy Roddick, the 2003 champion and the runner-up last year.
Federer is 13-1 against Roddick.
"It's a great record, but it doesn't help me," Federer said. "We'll see how it goes. Andy's always tough at the US Open."
Roddick advanced to the final eight when No 9-seeded Tomas Berdych stopped playing in the second set because of what appeared to be a breathing problem.
"I haven't been tested much this tournament so far," said Roddick.
Roddick was leading 7-6 (6), 2-0 when Berdych quit, making the Czech 0-9 against top-10 opponents at Grand Slam tournaments. Roddick's second-round opponent, Jose Acasuso, stopped because of a bad knee while trailing two sets to one.
At a changeover early in the match, Berdych asked to see a trainer and indicated he was having a hard time taking deep breaths. He then went out and broke Roddick twice to take a 5-3 lead and serve for the set. But Roddick broke back at love, then saved a set point in the tiebreaker.
He saw a doctor after leaving the court, then headed for blood tests to try to figure out exactly what was wrong.
Roddick went directly from Arthur Ashe Stadium to the practice court and hit for nearly an hour.
Earlier Monday, 2004 champion Svetlana Kuznetsova got off her stomach and closed the match, beating Victoria Azarenka 6-2, 6-3 to reach the quarterfinals.
Kuznetsova needed five match points, finishing it off with a strong, cross-court forehand that Azarenka chased into the corner, losing her hat on the way.
Earlier in the second set, No. 4 Kuznetsova was the one who tried without success to track down a shot. In the sixth game, she charged toward the net and skidded, doing the splits and winding up sprawled on the court.
The Russian got up easily and went on to eliminate the 18-year-old from Belarus. Kuznetsova next plays another unseeded opponent, Agnes Szavay of Hungary.
Szavay moved on by defeating Julia Vakulenko of Ukraine 6-4, 7-6 (1). Ranked No 31, Szavay is playing in her first US Open, her two other previous Grand Slam appearances ended in second-round losses at Wimbledon and the French Open this year.
Also Monday, Tommy Haas advanced, outlasting American hopeful and sixth-seeded James Blake 4-6, 6-4, 3-6, 6-0, 7-6 (4).
Haas next plays No 4 Nikolay Davydenko, who beat Lee Hyung-taik of South Korea 6-1, 6-3, 6-4.
No 18 Shahar Peer became the first Israeli woman to reach the US Open quarterfinals by beating No. 30 Agnieszka Radwanska 6-4, 6-1. Radwanska knocked off defending champion Maria Sharapova in the third round but couldn't keep up with Peer, who built a 20-4 advantage in winners.