Defending Australian Open champion Novak Djokovic said a confrontation with a spectator was the spark he "needed" to hold off Alexei Popyrin and avoid a shock second-round exit.
Djokovic, chasing a record-extending 11th men's title in Melbourne, looked far from his best in the four-set win.
The Serb told one spectator to "come down" to speak to him during the fourth set after being repeatedly heckled.
"Maybe that was needed for me to be shaken up a bit," said Djokovic, 36.
The world number one said he did not "want to be in those types of situations" but added the incident helped him to "start to find the kind of intensity on the court" that was required for him to see out a 6-3 4-6 7-6 (7-4) 6-3 victory.