Novak Djokovic survives Alexei Popyrin scare to battle into third round

The Serb, bidding for a record-extending 11th crown in Melbourne, was in deep trouble in the third set when errors began to flow and he had to save four set points.

With the packed night-time crowd on the edge of their seats, top seed Djokovic used his vast experience to win the pivotal tiebreak and then broke a dispirited Popyrin midway through the fourth set to finally seize control.

Djokovic breezed through the fourth set to rack up his 30th successive victory at the Australian Open -- his last defeat coming in 2018 -- but for the second successive round he was pushed hard and looked short of his best form.

"He missed an easy forehand and I was lucky to get away with that game," Djokovic, who was riled up by a heckling fan as the match neared its conclusion, said on court.

"He was the better player for a set and a half but the momentum shifted after the tiebreak."

Djokovic, bidding to claim a record 25th Grand Slam title, was kept on court for four hours during his opening-round victory over Croatian qualifier Dino Prizmic on Sunday.

But when he took the opening set against Popyrin in 39 minutes having lost only three points on serve, it seemed a more routine victory was on the cards.

Djokovic had a 13-1 record against Australian players at Grand Slams but the 24-year-old Popyrin was not about to go down meekly as he fired up his serve and forehand to start denting the Serb's armour.

The crowd burst into life when Djokovic faced a break point at 1-2 in the second set and Popyrin converted it with a deft volley.

Popyrin wavered, however, serving for the set at 5-3 with some errors gifting Djokovic the break. But in the following game, it was Djokovic's turn to wobble and the Serb's increasingly ragged forehand offered a couple of set points.

One was saved with an ace but Popyrin then produced a stunning lob to square the match.

Popyrin needed treatment on his calf midway through the third set but Djokovic, who came into the tournament with concerns over his wrist, also looked flat.

Serving at 4-5, the tension built as Djokovic missed a forehand, then an easy volley and then slammed a forehand into the net to offer up three set points. Djokovic held firm to save all three and then another as Popyrin eked out a fourth chance.

World number 43 Popyrin was made to rue those missed chances as Djokovic dominated the tiebreak and rolled on to victory despite some raucous fans doing their best to throw him out of his rhythm.

Djokovic's form will offer some hope to his third-round opponent, Argentina's Tomas Etcheverry.

"I was feeling a lot of mixed emotions on the court, not a great atmosphere to play in for me," Djokovic told Eurosport.

"It's frustrating when you have the hecklers."

Asked about his physical condition, a sniffly Djokovic said: "I don't want to get into the details about how I feel, but not feeling my best. But I've been in this situation many times."