Melbourne: Novak Djokovic tore off his shirt, flexed his sinewy muscles and roared in celebration, but for once the machismo was not misplaced.

After nearly six hours of the most gruelling final in grand slam history, the strutting Serb had shown he was not only supremely fit and talented, but as tough as they come.

The lanky world number one with the soft-spike hair came on court early on Sunday evening, played into the night and finished in the small hours of Monday.

Until the very last shot, blocking his way to the Australian Open title was the ferocious Rafael Nadal, the 10-time grand slam-winner with aggression to burn and a fearless competitive streak.

Djokovic's white shirt lasted just five games before he removed it in disgust on a steamy Melbourne evening and threw his racquet to the floor after being broken.

It was to be just the first act in a long, long night of plot twists and momentum changes which started tamely but slowly built into an epic.

Along the way, Djokovic rolled his right foot, punched the air in triumph and collapsed flat on his back after a punishing, 31-shot rally.

At the other end, Nadal treated the crowd to his full range of fist-pumps and Hispanic snarls as both players went for broke.

Rain fell, workers with towels mopped the court and the stadium roof was closed.

At the end of it all, around 1:40 am, it was Djokovic embracing his coach in triumph while Nadal was left to reflect on his most valiant defeat. Even the great Rod Laver watching from the stands had seen nothing like it.

The players won 369 points between them, made 140 unforced errors, played 55 games plus a tiebreak, and hit 101 winners. It lasted 5hr 53min, the longest grand slam final and a record for the Australian Open.

So it was no surprise that during the official speeches, chairs were brought out for the players, their eyes stark and staring from the adrenaline.

Afterwards, Nadal wished the crowd "good morning", and he was asked if he would watch footage of the match. "Too long. Highlights only," he said.

"You watch, you look around and you see the clock, three hours, four hours, five hours, finally five hours, 30 (minutes). Seems like it's never gonna finish, no?"

Djokovic said he had been through every type of pain for his fifth grand slam title, which he described as the best win of his career.

"You know, you are in pain, you are suffering, you know that you're trying to activate your legs, you're trying to push yourself another point, just one more point, one more game," he said.

"You're going through so much suffering your toes are bleeding. Everything is just outrageous, you know, but you're still enjoying that pain."