Rafael Nadal praised Dominic Thiem after being muscled out of the Australian Open in the quarter-finals by a superb performance from the Austrian.
World number one Nadal had hoped to equal Roger Federer's record of 20 grand slam singles titles, but that will have to wait after fifth seed Thiem powered his way to a 7-6 (3) 7-6 (4) 4-6 7-6 (6) victory to set up a clash with Alexander Zverev.
Zverev had joked of his rivals: "I'll have a cold glass of Coke sitting in my hotel room with my AC (air conditioning) hopefully watching them play for six hours."
It did not quite take that long but, after four hours and 10 minutes, it was Thiem who clinched another dramatic Melbourne encounter, joining Zverev in striking a much-needed blow for the 20-somethings against the old guard.
Nadal said: "It has been a very good match. He has been playing very well. Playing very aggressive, great shots. Even from difficult positions, he was able to produce amazing shots.
"I honestly didn't play a bad match. My attitude was great. Good, positive, fighting spirit all the time. I didn't give up in one moment during the whole match. I gave myself an opportunity until the last point.
"Of course I am sad. I lost an opportunity to be in the semi-finals of another grand slam. But I lost against a great opponent."
Thiem looked like he might have blown his chance when he played a horribly nervous game serving for the match at 5-4 in the fourth set but recovered impressively in the tie-break.
Nadal saved two match points, the second with a HawkEye challenge after a Thiem lob had been called in, but on the third the Spaniard netted a forehand.
Thiem said of the 5-4 game: "A special situation for me, serving for the match against Rafa. Such a really mentally tough situation. I couldn't handle it but I turned it round in the tie-breaker.
"I'm full of adrenaline, full of happy moments."
Thiem, beaten by Nadal in the last two French Open finals, had never reached the last eight here before but, if he can maintain this form, he will have a good chance of winning a first grand slam title.
Zverev into first grand slam semi
Alexander Zverev reached his first grand slam semi-final with a four-set victory over Stan Wawrinka at the Australian Open.
The 22-year-old German went into the clash having not dropped a set and recovered from a poor start to record a 1-6 6-3 6-4 6-2 victory.
Having been criticised for under-performing at the slams, there is a certain irony that Zverev's big breakthrough has come at a tournament where expectations were probably at their lowest.
Zverev had a difficult 2019 and arrived in Melbourne with his serve apparently in crisis and having lost all three of his matches playing for Germany at the ATP Cup.
But his serve has clicked back into gear here and he has shown the sort of efficiency that had proved elusive at the biggest tournaments.
He won just 11 points in the first set against 2014 champion Wawrinka, who felt his quarter-final victory over Daniil Medvedev was the best he had played since knee surgery two and a half years ago.
That came over five gruelling sets and this was perhaps a match too far, with the veteran Swiss unable to sustain the pace as Zverev moved through to a semi-final clash against either Rafael Nadal or Dominic Thiem.
The seventh seed is now only two victories away from being able to fulfil his promise to donate all his prize money to the wildfire relief efforts should he go on to lift the trophy.
Zverev said: "It feels awesome. I've done well in other tournaments, won Masters, won World Tour Finals but I never could break that barrier at a grand slam.
"You guys cannot imagine what this means to me and I hope this can be the first of many."
The German promised to donate the entire prize cheque of 4.12 million Australian dollars (approximately £2.15million) to the wildfire relief efforts should he win the title.
That seemed an unlikely occurrence at the start of the tournament, and Zverev said with a chuckle: "Easy to say in the first round, right? Yes it is still true. I hope I can make it happen. I made the people of Australia a promise. I will keep that promise if it happens."