I have a mental edge over Nadal: Djokovic

All the top three's charitable talk of new challengers ready to end their Grand Slam hegemony at the Australian Open has come to nothing and the top two seeds Novak Djokovic and Rafa Nadal will contest their third consecutive major final on Sunday.

The rivalry between Nadal and Serb Djokovic appears set to challenge that of the Spaniard's long double-act with former world number one Roger Federer.

But where Nadal and Swiss Federer's matchups inspired mutual admiration, the Spaniard's relationship with Djokovic, the man who poached his top ranking last year, is far more complex and the barbs have been flying from both camps in the leadup.

Defending champion Djokovic, dragged into a near five-hour slog with fourth seed Andy Murray on Friday, has a day's less rest to recover than Nadal, and was thus more happy to talk of their recent head-to-head record.

The losses, all in finals, included last year's Wimbledon and US Open crowns.

"On the other hand, it's a new year. It's a new challenge," added Djokovic. "It's a different situation. As I said, he has maybe a day advantage over me for recovery and for getting ready for the finals."

While pushed, Nadal finished his four-set semi-final against third seed Federer on Thursday full of running and brimful of confidence, having inflicted an eighth defeat of the Swiss in their record-equalling 10th Grand Slam encounter.

That allowed the 25-year-old the luxury of watching Djokovic on television as the Serb closed out the match against Murray with spare fuel in the tank, despite having appeared a panting, sweating wreck halfway through.

Djokovic, who also appeared to struggle before blasting fifth seeded Spaniard David Ferrer in straight sets in their quarter-final, blamed an allergy for giving him a blocked nose and breathing difficulties.

A skeptical Nadal, looking relaxed and assured in a white T-shirt, suggested it was mere naked gamesmanship.

"It's funny, no? I saw the match yesterday on the TV show on the channel seven when he was in the fifth set moving fantastically well, and they show images from two hours fifty (minutes) before and seems like he was destroyed," the 10-times Grand Slam champion said on Saturday.

"Two hours fifty later he was in perfect condition. So it is difficult to imagine that he has these problems. I don't know."

Then, Nadal had played a five-hour, 14-minute semi-final over compatriot Fernando Verdasco, the longest match on record at Melbourne Park, before beating Federer in a five-set classic for his first title on the blue hardcourt of Rod Laver Arena.

"I had only one day and Federer had two, no?" he said. "I was recovered for the final, so I think you can say it's unfair, yes, but not crazy unfair.

"Having one day off, I believe you are not in big trouble."

While fitness may ultimately decide who wins the tournament, a lack of it is unlikely to concern either Nadal or four-times Grand Slam champion Djokovic, bidding for his third title at Melbourne Park.

Nadal came to Melbourne Park brushing off queries about a shoulder injury, and despite suffering a painful knee twinge the night before his opening match, has steadily returned to his scrambling fist-pumping best.

Nadal's quarter-final win over Czech seventh seed Tomas Berdych, where he came back from being one point shy of a two-sets to love deficit, appeared the circuit-breaker and he later spoke of playing his best tennis since the first half of 2011 -- before his long run of losses to the Serb.

Prior to Murray, Djokovic had only conceded one set for the tournament, to gritty Australian former world number one Lleyton Hewitt, and for all his declared breathing issues, has motored through the tournament with a succession of clinical victories.

"(Nadal) has a fighting spirit. He has very few weaknesses. He's very eager and motivated to win the title -- as much as I am," said Djokovic.