Djokovic kisses the men's singles trophy after securing his sixth Australian Open tennis title, Jan 31, 2016. [Photo/Agencies]

"There's no doubt I'm playing the best tennis of my life over the last 15 months," the 28-year-old, who topped the ATP rankings for the whole of 2015, said.

"I do feel that I'm at the peak of my abilities and my career. I don't think about limiting my ambitions or what I might be able to achieve."

For Murray, distracted on his 11th visit to Melbourne Park by the illness of his father-in-law and the impending arrival of his first child, a dispiriting night ended up with a record of the wrong sort.

The Briton's defeat was his fifth in five finals at the Australian Open. Only his former coach Ivan Lendl has lost as many at one grand slam and he at least wedged three U.S. Open titles in between the defeats.

Murray gave it everything he had in the two-hour, 53-minute baseline battle that was compelling viewing throughout an engrossing and pivotal 80-minute second set.