Stefanos Tsitsipas completes epic comeback against Rafael Nadal to reach Australian Open semi-finals

Stefanos Tsitsipas staged a remarkable comeback to defeat Rafael Nadal in a five-set epic on Wednesday and book his place in the Australian Open semi-finals.

Fifth seed Tsitsipas looked to be heading for an early loss after being second best for the first two sets. But after hanging on and winning the third set tie-break, the 22-year-old Greek turned the match on its head to win 3-6, 2-6, 7-6, 6-4, 7-5.

"I don't know what happened after the third set – I fly like little bird, everything was working for me," said Tsitsipas, who hit 49 winners and 17 aces. "The emotions at the end were indescribable, they were something else."

The 22-year-old credited a composed temperament for his turnaround.

"I was able to be consistent with my mood and be calm in the crucial moments," he said. "I've been trying to keep everything to myself and I'm happy with my attitude I showed on the court."

It was just the second time Nadal had lost when two sets up in a Grand Slam, having previously fallen to Fabio Fognini in the third round of the 2015 US Open.

Nadal, 34, remains tied with Roger Federer on 20 Grand Slam titles, but Novak Djokovic can pull within two if he wins his 18th major trophy at Melbourne Park.

Tsitsipas will now attempt to reach a maiden Grand Slam final when he plays the in-form Daniil Medvedev in the semi-final.

"He's playing very well and is in good shape. I know he is going to give me a difficult time on the court," said Tsitsipas, who has a 1-5 record against the Russian. "I need to recover and do a nice ice bath."

He beat Nadal for just the second time in eight matches. Djokovic will play the other semi-final against Russian qualifier Aslan Karatsev on Thursday.

Nadal, sweating profusely in the muggy conditions, was in vintage form until a nerveless Tsitsipas turned the match on its head after snatching the tiebreak in the third set.

The momentum shifted towards Tsitsipas in the fourth set and he finally cracked Nadal's serve to force a deciding set.

Both players served well under pressure in a tense fifth set before Tsitsipas gained the pivotal break in the 11th game and then clinched his memorable victory with a backhand winner down the line.

Nadal was hoping to end a 12-year drought at the Australian Open, the only Slam he has not won multiple times.

Given Medvedev's imperious form, Tsitsipas is sure to face another battle in the semi-final.

The Russian fourth seed extended his winning run to 19 matches after outclassing compatriot Andrey Rublev 7-5, 6-3, 6-2.

Medvedev ended last season with back-to-back titles at the Paris Masters and ATP Finals before beginning this year by clinching the ATP Cup for Russia alongside Rublev.

However, teammates became opponents on Wednesday and Medvedev had little room for sentiment as he claimed a straight sets win in two hours and five minutes inside Rod Laver Arena.

Rublev has enjoyed little success against Medvedev and their latest meeting marked a fourth consecutive straight sets defeat by the 2019 US Open finalist.

Following his victory, Medvedev needed a massage on his left thigh before proceeding to his on-court interview and said he was cramping towards the end of the contest.

"Super tough, if you come to Australia and it's 40 (degrees) each day, it's tough but you get used to it but we've had a couple of days when it was 20 degrees," Medvedev, 25, said.

"We had some unbelievable rallies, I'm one of the first players to make Andrey so tired ... It's hard to play (a friend) but we're all so competitive, just need to win, get to that Grand Slam semi-final.

"That was one of my best matches ... I beat him in three sets not even with a tiebreak so I'm really happy."