All-conquering Novak Djokovic Sunday said a turbulent childhood where he had to queue for milk and bread in war-torn Serbia made him hungry for success, after he fought back from the brink to win his eighth Australian Open.

The 32-year-old needed to dig deep to rally from two sets to one down for the first time in a Grand Slam final and battle past fifth-seeded Austrian Dominic Thiem 6-4, 4-6, 2-6, 6-3, 6-4.

His eighth victory in eight finals at Melbourne Park handed him a 17th Major to move within three of Roger Federer's all-time 20.

Asked how he managed to keep winning in pressure situations, Djokovic said it stemmed from his early life. "My upbringing was in Serbia during several wars during the '90s, difficult time, embargo in our country where we had to wait in line for bread, milk, water, some basic things in life," he said. "These kind of things make you stronger and hungrier for success I think in whatever you choose to do.”

"That probably has been my foundation, the very fact that I came from literally nothing and difficult life circumstances together with my family and with my people. Going back to that, reminding myself where I came from always inspires me, motivates me to push even harder. That's probably one of the reasons why I managed to find that extra gear or necessary mental strength to overcome challenges when they present themselves."

The match against Thiem was one of those occasions.

'I was a bit shocked'

He looked in trouble after losing the second and third sets, with his energy levels down and a trainer telling him he was dehydrated.

"I definitely did not feel good. I didn't know what the next moment brings. I was trying to keep myself alive mentally as well, and emotionally," he said. "I was a bit shocked that I did feel that way because everything was fine before the match. For the first two sets, everything was okay. But it's something that you have to accept that you're going through. Those kind of circumstances really kind of force me to let things go and to really try to be in the moment and fight my way back."

Victory ensured Djokovic will once again be world number one when the new rankings are released on Monday, displacing Nadal. Federer remains third with Thiem moving up a place to a career-high fourth. It also moved him alongside Nadal (12 at the French Open) and Federer (eight at Wimbledon) as only the third man ever to win eight or more titles at the same Slam.

Djokovic said winning Major titles was the reason he kept playing tennis. "Obviously at this stage of my career, Grand Slams are the ones I value the most. They are the ones I prioritise," he said.

"Before the season starts I try to set my form, shape for these events where I can be at my prime tennis, mental and physical abilities. Grand Slams are one of the main reasons why I am still competing and still playing full season."