Australian Open: Djokovic considers best way forward after shock exit

The former world No 1 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.”

Roger Federer maintained his record of not having dropped a set at the tournament with a straightforward victory over Marton Fucsovics.

The 25-year-old Hungarian was a surprise face in the fourth round and acquitted himself well on Rod Laver Arena but ultimately proved no match for the defending champion, who won 6-4 7-6 (7/3) 6-2.

The victory sends Federer through to the last eight in Melbourne for the 14th time and 52nd overall in grand slams, where he is likely to be more severely tested by Tomas Berdych.

This was a first meeting for the pair, although Federer played Fucsovics’ coach Attila Savolt in the second round in Melbourne 16 years ago.

Federer was also playing during the day for the first time all tournament after three matches at night but had no problem making the adjustment and is the oldest man to reach the quarter-finals here since Ken Rosewall in December 1977.

The 36-year-old said: “I thought he played very well. Fast conditions, you have to have quick ideas and execute well and I think he did that very well.

“I had a hard time breaking through until two sets to love and a break.

“Credit to him for playing a great tournament, that’s what I told him at the net.”

Berdych has been flying under the radar this fortnight but, after beating Juan Martin del Potro in straight sets, he followed up with an impressive 6-1 6-4 6-4 victory over Fabio Fognini.