Novak Djokovic crashes out of Australian Open after struggling with elbow injury
Novak Djokovic must go back to the drawing board after suffering a recurrence of his elbow problems in a fourth-round loss to Chung Hyeon at the Australian Open.
The former world number one came into the tournament without having played a match since Wimbledon and was compromised again in a 7-6 (7/4) 7-5 7-6 (7/3) defeat by 21-year-old Chung, who played an extraordinary match.
Djokovic received treatment at the end of the first set and grimaced his way through the rest of the match, and he must now decide what path he wishes to take.
The six-time Australian Open champion left open the possibility of surgery when speaking ahead of the tournament, and he said of the elbow: "Unfortunately, it's not great. At the end of the first set it started hurting more. So I had to deal with it until the end of the match.
"I have to reassess everything with my team, medical team, coaches and everybody, scan it, see what the situation is like. The last couple weeks I played a lot of tennis. Let's see what's happening inside.
"It's frustrating, of course, when you have that much time and you don't heal properly. But it is what it is. There is some kind of a reason behind all of this. I'm just trying my best obviously because I love this sport. I enjoy training. I enjoy getting myself better, hoping that I can get better, perform and compete.
"Today was one of those days where, unfortunately, it was too much to deal with."
Djokovic's troubles should not in any way take away from the performance of Chung, who is the first Korean player to reach the quarter-finals of a grand slam.
He idolised Djokovic as a young player and it must have been like playing a mirror image for the Serbian as his opponent scrambled to retrieve seemingly impossible shots and turned defence into attack superbly.
Most impressively, he was ice cool at the most important moments on the biggest stage of his life.
Djokovic said: "Amazing performance. He was a better player on the court tonight. He deserved to win, no question about it.
"Whenever he was in trouble, he came up with some unbelievable shots, passing shots. From the back of the court, he was like a wall. It's impressive. I wish him all the best."
Chung is a quiet character but it was obvious how much he was enjoying himself and he whipped up the crowd after ending a brilliant rally with a superb passing shot.
"I'm just so happy," he said. "I don't know how I did it. I'm just happy to play with Novak again. It's great to have him back on the tour. I was just trying to copy Novak because he's my idol. I can't believe it. My dreams have come true tonight."
In one of the more unlikely quarter-finals in grand slam history, Chung will play American Tennys Sandgren, who had never won a slam match before arriving in Australia but followed up his second-round upset of Stan Wawrinka by defeating fifth seed Dominic Thiem 6-2 4-6 7-6 (7/4) 6-7 (7/9) 6-3.
"I definitely had a real pinch-me moment," said the 26-year-old. "Wow, this is hopefully real. If I wake up now, I'm going to be real upset."
For once, Roger Federer had to take a back seat but the defending champion is through to the last eight without having dropped a set, beating Hungarian Marton Fucsovics 6-4 7-6 (7/3) 6-2 in his latest outing.
There he will face a resurgent Tomas Berdych, who followed up his win over Juan Martin del Potro by defeating Fabio Fognini 6-1 6-4 6-4.