Stefanos Tsitsipas said he found "nirvana" on the tennis court as he recovered from two sets down to halt Rafael Nadal's bid for a record 21st Grand Slam title at the Australian Open on Wednesday.
Second seed Nadal was on course for a comfortable victory before Greece's Tsitsipas turned the quarter-final around to prevail 3-6, 2-6, 7-6 (7/4), 6-4, 7-5 in four hours and five minutes.
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.
The fifth seed turned the match on its head after snatching the tiebreak in the third set and clinched the memorable victory with a backhand down the line.
Known as occasionally a hot-headed player, the 22-year-old has made a conscious effort to take a calmer approach, which paid dividends when he was on the brink of elimination against a rampant Nadal.
"I wasn't thinking about a lot of things," said Tsitsipas, who hit 49 winners and 17 aces in his second win in eight meetings with Nadal.
"How would I describe myself? Nirvana. Just was there... playing, not thinking."
He added: "I woke up today and I felt really relaxed. I felt things would go my way.
"I was very serene during the match. Maybe the absence of a crowd kept me like this."
'Everything I dreamed of'
Tsitsipas said celebrating with his father Apostolos and his coaching team, among the few people at Rod Laver Arena during a state-wide coronavirus lockdown, was a "special moment".
"The way I was able to come back, the way I did, and how I fought against Rafa, was something I've never felt before," he said.
"To be able to hug my team and share that moment of appreciation was epic.
"It's everything I ever dreamed of."
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.
"He's someone that I really need to be careful with and just take my chances and press."
"I don't feel completely exhausted. With experience I have realized how to preserve my energy," he added, after his second five-set match of the tournament.
Defending champion and world number one Novak Djokovic will play the other semi-final against Russian qualifier Aslan Karatsev.
Nadal, 34, remains tied with Roger Federer on 20 Grand Slam titles, but Djokovic can pull within two if he wins his 18th major trophy this week.
Nadal was hoping to end a 12-year drought at the Australian Open, the only Slam he has not won multiple times.
