The 38-year-old became the first player to record 400 singles victories at the majors after a straight-sets victory over Dutchman Botic van de Zandschulp in Saturday night action at Rod Laver Arena.
The victory also saw 10-time AO champion Djokovic equal Roger Federer's record for most singles match wins at the tournament -- a staggering 102.
While outside temperatures still sweltered above 36C when Djokovic hit the court, the tour veteran clocked the historic mark with a 6-3 6-4 7-6 (7-4) win over the world No.75.
But a brain-snap by Djokovic in the second set could have ended in disaster, in scenes reminiscent of his 2020 US Open default.
The fourth-seeded veteran had won the first set 6-3 and was up 4-2 in the second.
Looking for another break against his big-hitting rival, Djokovic belted a ball away at the end of a rally, narrowly missing hitting a crouching ball-girl by centimetres.
"Oh careful, that was almost default," Stan commentator Colin Fleming said.
"That was so close to a default."
Australian chair umpire John Blom didn't issue a code violation but gave Djokovic a long glare, then spoke to him at the changeover.
After the match, Djokovic offered an apology when asked about the incident.
"That was not necessary and in the heat of the moment," he told reporters.
"I was lucky there and I'm sorry for causing any distress to the ball kid or anybody."
In 2020, the then-world No.1 was ejected from the US Open after he accidentally hit a line judge in the throat with a ball smacked in anger while he trailed fourth-round opponent Pablo Carreno Busta 6-5 in the first set.
Djokovic recovered in Melbourne and sealed the second set, but required a medical timeout early in the third.
A former world No.22 who won their previous meeting at Indian Wells last year, van de Zandschulp then broke the tennis great to take a 3-1 lead, but Djokovic hit back to level at 3-3.
The pair went toe-to-toe in the third set and, leading 6-5, van de Zandschulp had two set points, but the dogged Djokovic refused to succumb and blasted a serve to force a tiebreak.
Van de Zandschulp kept in touch at 3-3, but Djokovic forged ahead and wrapped up the win on his second match point.
He admitted he was relieved to get the job done in straight sets, with van de Zandschulp making inroads with his serve after some treatment for his shoulder while down 0-3 in the second set.
"It was a pretty good treatment I must say, it gave him a lot of firepower, he was serving extremely well from that moment onwards," Djokovic said.
"At the beginning of the second he did struggle with the arm ... then the tables turned and I must say I relaxed a little bit too much and was in trouble to close out the second set, and pretty much from that point on it was anyone's game.
"Really lucky to get out of the trouble with the set point in the third. He had an upper hand in that point.
"Just glad to overcome it in straight sets."
19°C