An ailing Novak Djokovic crashed out of the Australian Open in the fourth round as upcoming player Hyeon Chung clinically took advantage of the six-time champion's elbow injury to win 7-6 (7-4), 7-5, 7-6 (7-3). The Serbian, who had also struggled with his hip in the third round, was on the back foot from the off and failed to claw back in the first set before suffering further at the start of the second. It was clear that Djokovic, wearing a protective sleeve on his right arm, was struggling with his elbow as he repeatedly failed to hold serve and he received treatment before the second set.