Novak Djokovic’s Australian Open hopes are in the balance due to a torn stomach muscle.

On a night of high drama in Melbourne, world number one Djokovic was leading Taylor Fritz by two sets before suffering an injury to his right side which left him barely able to muster a forehand.

The reigning champion, eight-time winner and overwhelming favourite had looked on the verge of retiring injured with every post-rally grimace as American 27th seed Fritz reeled him in to level the third-round match.

But play was suspended for 10 minutes at 11.30pm while the crowd were told to leave due to a new Victoria government-imposed lockdown to combat an outbreak of the UK strain of coronavirus in the state.

Djokovic re-emerged to battle through the pain barrier and win 7-6 (1) 6-4 3-6 4-6 6-2.

However, the Serbian cut a gloomy figure when quizzed about continuing in the tournament.

He said: “I really don’t know, my friend. Right now, I know it’s a tear, definitely, of the muscle.

“So I don’t know if I’ll manage to recover from that in less than two days. I don’t know. I don’t know. I don’t know if I’m gonna step out onto the court or not.”

Upon securing an unlikely victory Djokovic’s scream of relief echoed around an eerily silent stadium, a stark contrast to the scenes just an hour earlier in the John Cain Arena.

There, before the curfew was enforced, Dominic Thiem survived a commanding performance from Nick Kyrgios, coming back from two sets down to win an epic encounter.

Controversial Australian Kyrgios whipped the late-night crowd into a frenzy as he raced ahead but Thiem somehow held himself together to stage a remarkable comeback, winning 4-6 4-6 6-3 6-4 6-4.

Melbourne’s headline act went through his big hits early on, with a break of serve in the first game, an underarm serve and tweener through the legs in the second, and disputed a net cord in the third.

The single break was sufficient to take the first set, and Kyrgios brought the house down when he clinched the second with an underarm ace.

The scenes resembled the Last Night of the Proms, which sadly will not be repeated for at least the next five days as the stands fall silent.

However, the encore belonged to Thiem, who had come from two sets down to beat Alexander Zverev in last year’s US Open final.

The Austrian third seed, facing two break points at the start of the third set, reeled off an astonishing 28 unanswered points on his serve.

Break points were becoming scarcer on either side until Thiem edged ahead for 5-3 in the decider, and he served out with a swish of the backhand sealing a memorable victory.

“A match against Nick on his favourite court, there are easier things to do,” smiled Thiem on court afterwards.

“That’s one of the tougher challenges we have in our sport, you never know what’s coming.

“I was fighting myself in the match but after the US Open nothing’s impossible. That match showed me giving up is never an option.

“I always prefer playing in front of a crowd, even if they are not for me. They are obviously for the local hero, there’s nothing wrong with that.

“I prefer that to playing in an empty stadium. Tonight was epic and a good last match before lockdown.”

Kyrgios, so often the bad boy of tennis, has won many admirers this week.

He said: “I left it all out there. I put myself in a position to win. I’m not upset. I’ve lost from two sets to love before. I’ve been here before and it’s all right.”

Earlier, unknown Russian Aslan Karatsev caused a major shock when he destroyed eighth seed Diego Schwartzman in straight sets.

The 27-year-old qualifier, ranked 114 in the world and playing at his first grand slam, stunned Argentinian Schwartzman 6-3 6-3 6-3.

Karatsev will play 20th seed Felix Auger Aliassime, who won the all-Canadian showdown with Dennis Shapovalov in straight sets, in round four.