Novak Djokovic limps into round three in Melbourne as injury worries remain

Djokovic, who also called for a drunk spectator who was heckling him to be thrown out, came into the tournament with the injury having picked it up playing in Adelaide a fortnight ago.

Novak Djokovic, right, leaves the court with the trainer (Dita Alangkara/AP)

Novak Djokovic survived a four-set battle with Enzo Couacaud to reach the third round of the Australian Open but concerns will be growing over the state of his left hamstring.

Djokovic took a medical timeout during the second set and appeared distinctly uncomfortable, grimacing and stretching, but he avoided joining Rafael Nadal and Casper Ruud in making an early exit, coming through 6-1 6-7 (5) 6-2 6-0 to set up a clash with Grigor Dimitrov.