But the defending champion didn't have it all his way, forced to refocus after a third set hiccup to seal a 7-6 (7-5) 6-3 2-6 6-1 victory on Rod Laver Arena on Monday night.

The win was the world No.2's 900th ATP career victory - the sixth highest in ATP history - and kept him on track for an unprecedented eighth crown at Melbourne Park.

"It was a New Year's resolution to enjoy more but it's easier said than done," Djokovic told Nine Network.

"Obviously when you are on the court, especially in my position I am expected to win most of my matches.

"There is a lot of pressure and a lot of different emotions involved so I definitely try to remind myself to stay present and really enjoy."

The 32-year-old Serb said that Rod Laver Arena was his happy place, given his unrivalled success at Open.

"It is great to be back in this arena - it has a very special place in my heart as this has been by far my most successful court in my career," he said.

Struff, the world No.37, unsettled Djokovic in the third set, breaking his opening serve.

Djokovic levelled before Struff again pulled ahead for a 4-2 lead and then wrapped up the set.

Djokovic gave his opponent credit for the fightback.

"In the second set I played very well and had a high percentage of first serves in," Djokovic said.

"Then in the third set he turned it around and he was not missing much and putting a lot of first serves in so credit for him fighting."

Despite the victory Djokovic said there was one shot he wouldn't be repeating in any coming matches.

Djokovic attempted a "tweener" during the first set while racing to play at the net, only for it to fall short.

He said he would leave such shots to Australian Nick Kyrgios, who has made the trick shot his own.

"Nick does it better than me, that is for sure," Djokovic said.

"I will probably not try that any more this tournament."

Australian Associated Press