MELBOURNE—Andy Murray cites a mental lapse in the third set as the turning point of the Australian Open final.

Novak Djokovic's 7-6 (5), 6-7 (4), 6-3, 6-0 victory gave him his fifth Australian Open title, with Murray winning just one game after going up 2-0 in the third set of the contest.

"I got distracted in the third set," he said, explaining that Djokovic "fell on the ground after a couple of shots. It appeared that he was cramping, and then I let that distract me a little bit.

"The fourth set, I mean, obviously I need to watch it back to see if I played badly. I mean, he was just ripping everything. Returns he was hitting on the baseline, this far from the line all the time. Once he got up a break, he just loosened up."

The sixth seed had been in the match until letting Djokovic regain the upper hand. "So, yeah, I'm frustrated at myself for letting that bother me at the beginning of the third set, because I was playing well, I had good momentum, and then just dropped off for like 10 minutes and it got away from me," he said. "So that's the most frustrating thing because I thought I obviously had opportunities in the first set. I couldn't quite get them. I managed to sneak the second. Then obviously was that break up."

The 27-year-old two-time Grand Slam champion could not explain why he had let it bother him, saying, "But, yeah, I play enough matches to be able to handle that."

Murray gestured and spoke angrily to his box during the match. He indicated that Djokovic's increased level of play caught him by surprise, and the pressure of the final meant it was more difficult to respond. "I think, like I said, the way he was moving at the end of the third set, he obviously started playing much better again. That contributed to some of it, as well," Murray said. "If someone's cramping in the final of a slam, with such a long way to go, you're feeling pretty good about yourself. Yeah, maybe, like I said, I dropped off for 10, 15 minutes there, and he got back into it. That was it. I don't know exactly why it was the case, but I've never really experienced that in a Slam final before. Maybe the occasion was something."

Murray did not know exactly what Djokovic's problem was, saying, "He obviously looked like he was in quite a bad way at the beginning of the third set and came back unbelievable at the end of that set. Then obviously the way he was hitting the ball in the fourth and moving was impressive. So, yeah, I don't know exactly what the issue was for him."

Djokovic, who also had a fall in the second set that appeared to affect his hand, did not point to anything specific. "No, I wasn't cramping, he said. "I was just weak. I went through the physical crisis in the matter of 20 minutes. And, honestly, didn't feel that too many times in my career."

It was the fifth Grand Slam final the two have played against one another, having split their other four contests.