Fatigue catches up with Djokovic

Serb Novak Djokovic applauded Roger Federer's play while bemoaning his own fatigue after losing 6-3 5-7 7-5 6-2 in the US Open men's semi-final on Saturday.

The 21-year-old appeared listless early on against Federer after needing almost 10 hours to battle past his last three opponents, including a five-set win over Spaniard Tommy Robredo in the last 16 and a four-set tussle against Andy Roddick.

"Roger was playing good," third seed Djokovic told reporters after being outplayed by the four-times defending champion.

"He deserved to win, absolutely. I was just a little disappointed from my side that I wasn't able enough physically to give him a challenge.

"I think I played well that second set and it was on serve in that third one. I was just unlucky to lose that third set and then more or less routine in the fourth for him.

"Overall, it's been a very exhausting tournament mentally and physically for me so I'm happy that I got to the semi," the Australian Open champion added.

"If you finish a couple of matches at 1:00 in the morning and then you go to sleep at 4:00 and then two days afterwards you got to play at 11:00 or 12:00, it's not really the best thing. But what could I do? I had bad luck."

Djokovic, who beat Federer en route to his first grand slam title at the Australian Open in January, had lashed out at Roddick after their quarter-final, sparking jeers from the crowd.

Nadal vs Murray

The second men's semi-final, between Rafael Nadal and Andy Murray, was scheduled to resume last night.

The match was stopped on Saturday due to inclement weather.

Murray was leading 6-2 7-6 3-2 and Nadal up a break in the third set when play was halted.