Andy Roddick (hamstring) retires

MELBOURNE, Australia -- Andy Roddick's attempt to win his first Grand Slam title in nearly a decade ended Thursday at the Australian Open when he had to retire from his second-round match because of a right hamstring injury.

The former No. 1, whose lone major singles win came at the 2003 U.S. Open, was trailing Lleyton Hewitt 3-6, 6-3, 6-4 when he called the trainer to his courtside chair. He then walked over to Hewitt and shook the Australian player's hand, unable to continue.

Roddick had fallen to the court in the second set, but continued playing despite being in obvious pain from the leg injury.

"It's a miserable, terrible thing being out there compromised like that," Roddick said of his attempt to play with the injury. "I wanted to see what I could do. You don't really have much time for clarity in that situation. He's a tough guy to play ... he knew what was going on."

Trailing 2-0 in the second set, Roddick moved suddenly to his
right to reach a Hewitt forehand, and seemed to overstretch his
right leg, rolling over on his right ankle. Hewitt won that point
and the next two for a 3-0 lead, then Roddick took a medical

Hewitt said the injury was "a nightmare for both of us."

"Obviously he stretched something," Hewitt said. "It's not easy for the person up the other end of the court. It's hard to concentrate when they're having injury timeouts.

"Andy's a great competitor ... he's similar to me. He plays with his heart on his sleeve, has that never-say-die attitude as well. It's never easy to play injured or to pull out of a match. It's not a good feeling."

Roddick looked lethargic in the second and third sets, rarely chasing down shots and walking slowly between points with his head hanging down. He threw his racket into the wall at one point and argued with the chair umpire after a video replay showed that one of Hewitt's shots -- originally called out -- actually hit the line.

The 30-year-old Hewitt, who has won two major titles and was a finalist here in 2005, will play 21-year-old Milos Raonic of Canada in the third round.

Roddick's status for mixed doubles appears uncertain. After seeing his injury, Serena Williams tweeted: "Oh no my dubs partner!!!!! :("

Top-seeded Novak Djokovic, the world's top-ranked player, advanced earlier in his second-round match.

Playing against Santiago Giraldo, ranked 55 places behind him, Djokovic made four straight unforced errors in the fifth game to hand the Colombian the first service break of the match. But Djokovic quickly broke Giraldo to love in the next game and went on to win the next seven on his way to a 6-3, 6-2, 6-1 victory, playing much more like the man who won three Grand Slam singles titles and 41 matches in a row last year.

"I maybe started a little too defensive because he was hitting the ball very strong," Djokovic said. "But then after, it was the other way around."

A title this month would put him in select company. Only four players -- Rod Laver, Pete Sampras, Roger Federer and Rafael Nadal -- have won three straight Grand Slam singles tournaments, and Djokovic could join them following his wins at last year's Wimbledon and U.S. Open.

Second-seeded Nadal and third-seeded Federer, who are in the other half of the draw here, play back-to-back matches Friday at Rod Laver Arena.

Fourth-seeded Andy Murray, who lost to Djokovic in the final here last year, also advanced Thursday, beating Edouard Roger-Vasselin of France 6-1, 6-4, 6-4.

Murray is playing his first Grand Slam tournament since hiring eight-time major champion Ivan Lendl as his coach.

"It's been good; he's obviously one of the greatest players ever," Murray said. "He's got so much experience and he's very funny guy. You wouldn't probably expect it by the way he was on the court, similar to myself."

Sixth-seeded Jo-Wilfried Tsonga, who lost the 2008 Australian final to Djokovic, advanced 7-5, 6-4, 6-4 over Ricardo Mello of Brazil, while No. 5 David Ferrer struggled early against American Ryan Sweeting before coming back to win 6-7 (4), 6-2, 3-6, 6-2, 6-3.

No. 9 Janko Tipsarevic and No. 27 Juan Ignacio Chela also progressed. Frenchman Michael Llodra beat No. 32 Alex Bogomolov Jr. 6-1, 6-3, 4-6, 5-7, 6-4, and Portugal's Frederico Gil beat No. 26 Marcel Granollers in four sets.

Djokovic, for all his success at Rod Laver Arena -- his first Grand Slam title in 2008 and then again last year -- doesn't have any feeling of superiority on the tournament's center court.

"I don't think anybody is invincible," he said. "It's a matter of the confidence that you have, self-belief on the court, qualities as a player, being out there physically, mentally fit, being able to perform your best on a day-to-day basis.

"It is true, from one side, that when I step in there I feel that I belong there, that I know what to do. I feel more confident maybe than the other courts around the world."

Information from The Associated Press was used in this report.