By Larry Fine

NEW YORK (Reuters) - Novak Djokovic capped one of tennis's greatest seasons with a awe-inspiring U.S. Open triumph on Monday that could just signal an end to the sport's obsession with "Rafa v Roger" finals.

"He's jumped up a level," Wilander told Reuters. "I think this is the very beginning. He may be riding the wave, but it's not like the wave is going to end. This is how good he is."

Djokovic struggled with rib pain, lower back pain and cramping and needed a medical timeout and pain killer to carry on in a punishing final but stubbornly refused to yield.

"At this level you need those tough matches against top guys," said the Australian Open and Wimbledon champion. "To get confidence that you can really win majors and win the big matches.

"It's just that I'm hitting the shots that I maybe wasn't hitting in the last two, three years now. I'm going for it. I'm more aggressive and I have a different approach to the semi-finals and finals of major events."

Djokovic showed his go-for-broke attitude in surviving his semi-final when, down match point in the fifth set after clawing his way back from two sets down, he ripped an all-or-nothing forehand return across court for a jaw-dropping winner that destroyed Federer's spirit.

"I was always kind of trying to wait for their mistakes," the Serb, who replaced Nadal as world number one earlier this year, said about his attitude in the past.

"Not really having the positive attitude and kind of belief that I can win."

"I had the rib problem and they had to mobilize my back as well and some cramps in the leg," said Djokovic, who had grabbed at his back after several overhand shots and serves.

"I felt the most discomfort and pain with my serve, so I tried to go more for the precision rather than for speed," said the Serb, forced to spin in deliveries at about 90 miles per hour.

"I had to make the points very short, because it's obvious that he is the one that's physically fitter than me on the court today after the third set was done.

"I knew that and I had to go for my shots, and I did."

Nadal was gracious in his praise of Djokovic.

"This season he's (been) fantastic. His level is really, really high," 10-time major winner Nadal told reporters after congratulating the winner on the court.

"Obviously, I'm disappointed now. But this guy's done unbelievable things. So just congratulate Novak. What you did this year is probably impossible to repeat."