The world No.1 had more than just rising Canadian star Denis Shapovalov against him on Rod Laver Arena during his 6-3 6-4 4-6 6-0 win on Saturday.

Djokovic was miffed when the large crowd turned against him and erupted in cheers after he served a double fault that gave Shapovalov a break in the third set to go up 5-4.

Already fuming after letting a 4-1 lead slip, Djokovic gave the crowd a surly thumbs up as he walked to his chair and was then given a code violation for a verbal obscenity.

World No.27 Shapavolov made the most of the Serbian's red mist and sealed the third set with a booming forehand winner.

Djokovic left the court between sets to change his shirt, plus regain his composure and focus - and then he didn't give his opponent a sniff.

The 31-year-old said after winning 14 grand slam titles he should know better than to lose his cool.

"At 4-1, I was agitated and it should not happen to me, I know better - I have experience," Djokovic said.

"But it does happen, I guess and I allowed him to come back to the match.

But I like the fact that I was tested, as well, because you want to be tested, especially as you are moving along in the tournament.

"Matches and opponents are going to get tougher."

The win continued Djokovic's run of 17 grand slam victories, including the Wimbledon and US Open titles, and kept him in the hunt for the seventh Melbourne Park crown.

Almost at the halfway point, he felt his game was in good shape.

"Other than the little let down that I had I thought I played well so things are progressing well," he said.

The top seed next takes on Russian world No. 29 Daniil Medvedev, who earlier accounted for Belgian David Goffin in straight sets.

Australian Associated Press