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.
