New York - World No 1 Roger Federer advanced into his 34th consecutive Grand Slam quarter-final without touching a racket on Monday when American Mardy Fish withdrew from their US Open match for health reasons.
The 31-year-old Swiss star, seeking his 18th Grand Slam title and sixth US Open crown, advanced into a last-eight matchup against Czech sixth seed Tomas Berdych, who dispatched Spanish 11th seed Nicolas Almagro 7-6 (7/4), 6-4, 6-1.
"I probably need to have something more than 100 percent," said Berdych, who has lost 11 of 15 career meetings to Federer.
The walkover stretched Federer's record for consecutive quarter-final Grand Slam appearances in the Open era to 38, three shy of the record 41 achieved by American Jimmy Connors.
Federer, who won his 17th Grand Slam title in July at Wimbledon, has not dropped a set in the Flushing Meadows fortnight.
Fish missed two months of the season earlier this year because of a heart problem, being hospitalised after the Miami Masters event in March when his heart rate increased to three times its normal resting pace.
Fish, 30, then had a cardiac catheter ablation in Los Angeles on May 23 to address his heart condition.
Berdych, who took only two hours to reach his first US Open quarter-final, has won three of his past six meetings with Federer, including a US Open tune-up last year in Cincinnati and a 2010 Wimbledon quarter-final.
Berdych finally reached the last eight after 10 tries with his 200th career hardcourt triumph. He joined Petr Korda and Ivan Lendl as the only Czech men in the Open era to have reached the quarter-finals at all four Grand Slam events.
"I'm very happy that I can compete in all Grand Slams at least in quarter-finals. It helps my confidence," Berdych said.
At last January's Australian Open, Berdych was fuming at Almagro, accusing the Spaniard of hitting a ball at his face while he was at the net during a rally in a fourth-round match. The ball struck him on the arm.
Spectators booed Berdych for refusing to shake hands with the Spaniard after the match, but the Czech said Almagro's apology was not enough to satisfy him.
Berdych dismissed the acrimonious incident this week as "nothing at all", noting they have since split two ATP matches, although this was their first Grand Slam meeting since.
They clasped hands after Monday's match at Louis Armstrong Stadium, Almagro flashing a quick smile at his conquerer as they met at the net.
Almagro, 27, figures to replace injured Rafael Nadal on the Spanish Davis Cup team that will host the United States next week in a semi-final tie. Almagro is unbeaten in four Cup singles matches so far this year.
Berdych, whose best Grand Slam result was a 2010 Wimbledon final loss to Nadal, improved to 7-3 lifetime against Almagro and snapped a five-game losing streak to top-20 rivals dating to a Rome victory over Almagro last May.
Berdych took three of the last four points to win the first-set tie-breaker, a forehand volley winner claiming the set after 48 minutes.
"It was really close, especially in the first set," Berdych said. "It was a fight for every point. It was a tough match."
Almagro had a break point in the fourth game of the second set but Berdych erased it with a 127 mph ace and then broke Almagro in the seventh game and held serve twice more to take the second set.
Berdych broke at love to begin the third set and again in the third and final games.