Novak Djokovic beat Grigor Dimitrov in straight sets – 7-6 (9-7) 6-3 6-4 – to move in the last 16 of the Australian Open, despite a difficult performance from the world No. 5 who was visibly struggling to move at points during the match.

Djokovic, arguably the favorite to win the competition after Rafael Nadal and Casper Ruud were knocked out, came into Saturday’s clash carrying a hamstring injury. However, he seemed to ease those worries as he broke Dimitrov’s serve in the first game.

But Djokovic pulled up feeling his hamstring later in the first set and was forced to take a medical timeout after winning a grueling tiebreak.

After some treatment, Djokovic returned as a new man and took advantage of Dimitrov’s loose play to take the second set comfortably.