Berdych clips Federer's wings

Roddick bids adieu to the game as he bows to Del Potro in fourth round

Roger Federer was knocked out of the US Open on Wednesday when he lost a quarterfinal thriller to Tomas Berdych just hours after his old rival Andy Roddick bid a tearful farewell to his tennis career.

Federer was unable to conjure up any of his old magic as Berdych stormed to a surprise victory, 7-6, 6-4, 3-6, 6-3, handing the world number one of his earliest exit from Flushing Meadows in nine years.

"It couldn't be better," Berdych said in a courtside interview. “There is no better feeling. There is no better moment than this one."

Federer could not hide his disappointment after arriving in the Big Apple full of hope following his win at Wimbledon in July.

"There were so many moments I thought, man, it's just not happening for me," said the five-times US Open champion. "It was just a very disappointing match for me."

Roddick made his final appearance at Arthur Ashe Stadium when he lost to Juan Martin del Potro in the fourth round, while Andy Murray and Maria Sharapova both dug themselves out of trouble to stay alive on a drama-charged day at the last Grand Slam of the year.

Only Serena Williams and Novak Djokovic had an easy time, both romping to comfortable victories to enhance their status as the favourites for the singles titles.

Djokovic was in complete control of his fourth round match against Stanislas Wawrinka, leading 6-4, 6-1, 3-1, when the Swiss called it quits in one of five matches that were held over from Tuesday because of rain.

Sharapova needed all her fighting qualities to come from behind and beat Marion Bartoli of France 3-6, 6-3, 6-4 and reach the semifinals for the first time since she won in New York in 2006.

Williams, full of confidence and self-belief, demolished Serbia's Ana Ivanovic in less than an hour to raise hopes of an American winner after Roddick departed.

"I feel like I'm going to get more focused and serious and start playing Serena tennis in the next couple of rounds, if I get to play two rounds. That's my goal," she said.

Williams will play Italian Sara Errani in Friday's semifinals after she defeated her doubles partner Roberta Vinci 6-2, 6-4.

Olympic champion Murray produced an extraordinary turnaround to beat Croatia's Marin Cilic 3-6, 7-6, 6-2, 6-0 on a gusty Louis Armstrong court.

The Scot lost the opening set then fell two service breaks down at 5-1 in the second, before rallying back to win, reeling off the last 11 games in a row.

"It wasn't the best of starts," Murray said. "He got nervous towards the end of that (second) set once ... then I played a great match after that."

Serbia's Janko Tipsarevic beat German Philipp Kohlschreiber 6-3, 7-6, 6-2 and will face Spain's David Ferrer in Thursday's quarters.

Djokovic will square off on Thursday night with the towering Argentine Del Potro, the 2009 US Open champion, while Murray faces Berdych, who has been a thorn in Federer's side before, most famously in 2010 when he beat the Swiss master at Wimbledon. 

"There is something in my game that he doesn't like and it makes him struggle a bit, I would say, and maybe bring him out of his comfort zone that he always likes to be on court," Berdych said.

Roddick, the face of US men's tennis for most of the past decade, was reduced to tears after losing 6-7, 7-6, 6-2, 6-4 to Del Potro.

With his parents and wife watching from the stands, the 2003 champion said he was leaving the game with no regrets after 13 years as a professional.  "I've loved every minute of it," he said. "It's been a road, a lot of ups, a lot of downs, a lot of great moments."

Paes-Stepanek in semis

Leander Paes and his Czech partner Radek Stepanek stormed into the semifinals of the men’s doubles event after getting the better of Julian Knowle of Austria and Slovakia’s Filip Polasek in straight sets. The fifth-seeded Indo-Czech combo took just 74 minutes to outplay their opponents 6-2, 6-4.

The Indo-Czech pair will next take on the sixth-seeded Spanish combo of Marcel Granollers and Marc Lopez, who had defeated Bruno Soares of Brazil and Austria’s Alexander Peya 6-3, 6-4.

Results: Men (quarterfinals, prefix denotes seeding): 6-Tomas Berdych (Czech) bt 1-Roger Federer (Sui) 7-6(7-1), 6-4, 3-6, 6-3;  3-Andy Murray (Bri) bt 12-Marin Cilic (Cro) 3-6, 7-6 (7-4), 6-2, 6-0.

Fourth round: 7-Juan Martin del Potro (Arg) bt 20-Andy Roddick (US) 6-7 (1-7), 7-6 (7-4), 6-2, 6-4 ;  2-Novak Djokovic (Srb) bt 18-Stanislas Wawrinka (Sui) 6-4, 6-1, 3-1 (retd); 8-Janko Tipsarevic (Srb) bt 19-Philipp Kohlschreiber (Ger) 6-3, 7-6 (7-5), 6-2.

Women (quarterfinals): 4-Serena Williams (US) bt 12-Ana Ivanovic (Srb) 6-1, 6-3; 3-Maria Sharapova (Rus) bt 11-Marion Bartoli (Fra) 3-6, 6-3, 6-4;  10-Sara Errani (Ita) bt 20-Roberta Vinci (Ita) 6-2, 6-4.