My energy completely collapsed: Djokovic

Novak Djokovic has confessed to physically collapsing during his five-set Australian Open final comeback win over Dominic Thiem.

NOVAK DJOKOVIC Picture: Quinn Rooney/Getty Images

A stressed-out Novak Djokovic admits he "couldn't believe what was happening" after surviving a physical and psychological meltdown to win a mind-blowing eighth Australian Open crown.

A winner of the longest grand slam final in history, a near-six-hour epic against Rafael Nadal in 2012, Djokovic was unable to explain his ordeal on Sunday night.

"Tonight it was toe-to-toe battle. I was on brink of losing that match. I didn't feel great on the court at all," Djokovic said after his 6-4 4-6 2-6 6-3 6-4 escape against Dominic Thiem.

"It was quite surprising, to be honest, because I felt it started off well.

"But I played a couple of doubles, then the energy dropped an then the whole thing just started happening. I couldn't believe what was happening.

"Dominic started dominating from back of the court and won two sets pretty easily.

"I didn't have any injuries and it was very strange to me because I've done things pretty much the same as I always do.

"My energy completely collapsed. Every time I would toss the ball, I would feel dizzy.

"We were trying to do everything possible within the circumstances to kind of find a way to rejuvenate, I guess, and I was lucky."

Looking resigned to defeat, the Serbian ironman somehow regrouped to claim an dramatic win in a minute shy of four hours to clinch a 17th grand slam title.

"I did talk to the doctor and she did assess an evaluate me an she told me that I have maybe few conditions and things like that," Djokovic said.

"But it's not much you can do but get energy gels and bars and lots of liquid and she told me I was dehydrated so I tried to drink as much as I can, I guess.

"There was definitely an emotional aspect to all of this. With all the experience that I have had, I'm still nervous, still stressed out about what's going to happen, how am I going to play.

"Then there was one point where I just said 'OK, I have to accept it. It is what it is. Let's try to do everything possible to come back.'

"And then I guess the fortune was on my side."