An exhausted Novak Djokovic retired during the fourth set of his Australian Open quarter-final against Andy Roddick.
Defending champion wilts in Melbourne heat, Roddick into last four
Novak Djokovic's Australian Open title defence came to a premature end when he retired from his quarter-final against Andy Roddick due to heat exhaustion.
Djokovic, the third seed, heeded medical advice to quit while trailing 6-7 (3-7) 6-4 6-2 2-1 in soaring temperatures on the Rod Laver Arena.
There had been no indication of the problems to follow as the Serbian edged a tight opening set in a tie-break.
Roddick hit back to take the second set 6-4 courtesy of a solitary break in the seventh game.
At the start of the third set Djokovic started looking towards the players' box between each point and, after holding serve for a 2-1 lead, called a medical time out.
He looked exhausted when play resumed and promptly losing the next five games to surrender the set.
"No more"
Roddick missed four break points in the first game of the fourth set and, while Djokovic battled back to hold, the effort appeared to sap his last reserves of energy and his seventh-seeded opponent won the next game then broke him to love.
Djokovic walked off court to consult the doctor and returned to tell chair umpire Carlos Ramos of Portugal "no more", before he went to congratulate Roddick, who has now advanced to his fourth semi-final at Melbourne Park.
The on-court temperature was as high as 35 degrees Celsius (95 Fahrenheit) and Djokovic's withdrawal follows a similar situation in the women's tournament on Monday when Victoria Azarenka retired due to heat exhaustion while a set up on Serena Williams.
"Well, the main reason (for retiring) is cramping and soreness in the whole body," Djokovic explained.
"I think the people could see that I was struggling with movement.
"(I) really tried my best but sometimes you can't fight against your own body."
The 21-year-old has now retired from matches three times in less than three years while losing in the latter stages of a Grand Slam tournament.
He withdrew during the quarter-finals of the 2006 French Open when two sets down to Rafael Nadal and hoisted up the white flag again during the 2007 semi-finals at Wimbledon, also against Nadal.
Justified
"I did have some retirements but I always retired with a reason," he added. "Whenever I retired, I retired because I felt I cannot go on... that's the only reason.
"There is absolutely no question about whether I have motivation and will and desire to continue the match and defend my title.
"There is absolutely no doubt that I have it in me. My mind wanted me to continue."
Roddick, who will play second seed Roger Federer in the semi-finals, had been oblivious to his opponent's physical struggles.
"To be honest I didn't know (he was sick) until he called for help there. That's disappointing," Roddick said.
"I feel bad for Novak right now. He worked so hard for this last year. To not get a fair chance to defend his title, that's too bad."
