Roddick sent into retirement; Djokovic cruises

Andy Roddick of the US reacts to missed point against Juan Martin Del Potro of Argentina during their men's singles match at the US Open tennis tournament in New York September 5, 2012.  [Photo/Agencies]

NEW YORK - Andy Roddick bid a tearful farewell to his tennis career when he was beaten by Argentina's Juan Martin del Potro in the fourth round of the US Open on Wednesday while defending champion Novak Djokovic eased into the quarters.

The face of US men's tennis for most of the past decade, an emotional Roddick went into retirement after losing 6-7 7-6 6-2 6-4 in the fourth round.

"I've loved every minute of it," he told the crowd at Arthur Ashe Stadium. "It's been a road, a lot of ups, a lot of downs, a lot of great moments."

His farewell provided an poignant touch to a day which saw Djokovic sail into the quarter-finals with some help from his opponent while Maria Sharapova clawed back to reach the women's semis for the first time since she won the title six years ago.

Djokovic was in complete control of his fourth round match against Stanislas Wawrinka, leading 6-4 6-1 3-1, when the Swiss 18th seed said he was unable to continue so called it quits.

"I really don't know exactly what it was but by the look of it, I think it was probably a dizziness or something," said Djokovic, who has yet to drop a set in the tournament.

"He served well, he played well, but you could see that he didn't feel great on the court."

Sharapova needed all her fighting qualities to come from behind and beat Marion Bartoli of France 3-6 6-3 6-4 in one of five matches that were held over from Tuesday because of rain.

Bartoli led 4-0 overnight and wrapped up the first set when play finally resumed after another morning shower but Sharapova regained her composure to win the next two and book a semi-final date with world number one Victoria Azarenka.

"It's so long since I've been back to this stage at the U.S. Open. A little bit of luck always helps," the Russian said.

'Brilliant Career'

Sara Errani booked her place in the semis for the first time when she defeated her doubles partner Roberta Vinci 6-2 6-4 in an all-Italian match.

"A quarter-final with your best friend, of course, is difficult," said Errani. "We know each other very well, we've played together many times so it was strange to see her on the other side of the net."

Serbia's Janko Tipsarevic beat German Philipp Kohlschreiber 6-3 7-6 6-2 after the foul weather cleared long enough for the tournament to get back on schedule amid fears it would spill into a third week for a fifth straight year.

Roddick surprisingly announced last week that he would hang up his racquet after a 13-year professional career following the year's final grand slam.

The 30-year-old began the match well, winning the rain-delayed first set in a tiebreak, but could not keep up with the towering and younger Del Potro, who won the U.S. Open in 2009.

With the win, Del Potro advanced to Thursday's quarter-finals against Djokovic, but the plaudits still went to Roddick.

"Andy has been an outstanding ambassador for our sport and our country, always carrying himself with the character and class that define a champion," United States Tennis Association Chairman Jon Vegosen said in a statement.

"We could not be more proud of Andy and all that he has accomplished in his brilliant career, and we wish him every success and happiness in his retirement from the pro game."

Blessed with a powerful and a ferocious will to win, Roddick has been the torchbearer of American tennis since Pete Sampras and Andre Agassi retired.

He won the US Open, his lone grand slam title, in 2003 and briefly reached the top of the world rankings. He also made a second U.S. Open final and three Wimbledon finals, but lost them all to Roger Federer.

With his wife and parents in the stands, Roddick struggled to keep his emotions in check as the realisation that his career was over began to sink in, wiping tears from his eyes.

"One thing I'm not scared about retirement is the people I go home to," said Roddick. "They are great and I appreciate it."