Argentina's Juan Martin del Potro advanced to the quarterfinals of the U.S. Open with a 6-7 (1-7), 7-6 (7-4), 6-2, 6-4 win here Wednesday over Andy Roddick, a victory that sent the American into retirement.

The match-up of U.S. Open champions began Tuesday but was suspended by rain and resumed Wednesday with Roddick leading 1-0 in the first-set tiebreaker, which the American went on to win 7-1 against a lethargic Del Potro.

The two players had exchanged breaks of serve in the first set, but neither player managed even a break point in the second set, and Del Potro found himself faced with a must-win tiebreaker to avoid a two-set hole.

But the Argentine came alive with some strong returning when he needed it most to win that tiebreaker 7-4 and alter the momentum of the match.

He then proceeded to break Roddick's serve at the start of the third set en route to an easy 6-2 win and the writing was on the wall for the 30-year-old American, who had announced prior to his second-round match on Friday that this tournament would be his last.

Roddick went down a break in the fourth set and faced a match point when serving at 3-5, prompting the crowd to erupt with cheers for their favorite.

The American, known as one of the great servers in the history of tennis, managed to dig himself out of that hole with the help of his best weapon but that only delayed the inevitable as Del Potro served the match out one game later.

"It was really tough moment for me and for him, also. Last point of his life. The crowd was amazing for both players. I really enjoyed in that way, but it wasn't easy for me to play," the Argentine said in the post-match press conference.

"I played better than my last match. I was really high intensity during all the match, and Andy played really well."

The charismatic American, meanwhile, gave an emotional farewell speech afterward in which he soaked in the admiration of the large crowd at Arthur Ashe Stadium.

"Since I was a kid, I've been coming to this tournament and I felt lucky just to sit where all of you are sitting today and to watch this game and to see the champions that have come and gone," Roddick said.

"I've loved every minute of it," the American former world No. 1, who captured his one and only Grand Slam event in New York in 2003, said to rousing applause.

Roddick retired while still able to go toe-to-toe with the world's best players, but he explained last week that he is suffering from a series of nagging physical ailments and no longer has the physical ability or motivation to train day-in and day-out.

Del Potro, who won the 2009 U.S. Open, will next take on Serbian world No. 2 and defending champion Novak Djokovic, who advanced to the quarterfinals when his opponent, Switzerland's Stanislas Wawrinka, retired with an injury with Djokovic leading 6-4, 6-1, 3-1.

Djokovic holds a 5-2 advantage in the head-to-head matchup and won their last encounter at a U.S. Open tune-up event last month at the Western & Southern Open in Cincinnati, a tournament that - like the U.S. Open - is played on hard courts.

Del Potro, however, defeated the Serb in the men's singles bronze medal match at the London Olympics.

Those two will square off on Thursday, while the other quarterfinal in the bottom half of the draw will pit Serbia's Janko Tipsarevic against Spain's David Ferrer.

In the top half of the draw, Scotland's Andy Murray advanced to the semifinals with a four-set win Wednesday over Croatia's Marin Cilic, while No. 1 Roger Federer will square off in the night quarterfinal match against Czech Tomas Berdych.

The U.S. Open is the last of the four Grand Slam events, the biggest tournaments on the tennis calendar. EFE