Fourth seed Stefanos Tsitsipas prevailed after an epic fourth-round battle with American Taylor Fritz, coming back from a set behind twice to win 4-6, 6-4, 4-6, 6-3, 6-4 and reach the Australian Open quarter-finals on Monday.
The Greek star ended Fritz's campaign at the Rod Laver Arena to set up a clash with Italian Jannik Sinner, aiming to reach the semi-finals in Melbourne for the third time in his career.
Tsitsipas looked out of sorts at times but his experience on the big stage made the difference as he got the decisive break in the fifth set before claiming victory.
Fritz, playing in his first Grand Slam fourth round, converted only two of his 15 break points and will rue a missed opportunity to become the first American male to reach a Grand Slam quarter-final for two years.
"It was an epic match. I gave everything out on the court today, I am very proud of myself with the way I fought and the way I stayed consistent in the moments that were close and crucial," Tsitsipas said.
"I am overwhelmed, it's too much, the stadium was on fire, it's too good to be true.
"I knew it was going to get physical and I kept reminding myself to get in there and do the work, don't give up, give it a little bit more patience and in the end it paid off."
Tsitsipas became the first Greek player to reach a Grand Slam final when he lost to Novak Djokovic in last year's French Open final after leading by two sets.
He also beat both Rafael Nadal and Roger Federer on his way to his two previous semi-final appearances at the Australian Open.
Meanwhile, Daniil Medvedev kept alive his bid for a second Grand Slam title after coming through a tricky match against Maxime Cressy to book his second Australian Open quarter-final.
The Russian second seed found the American's serve-and-volley approach a tough nut to crack at Margaret Court Arena and his frustration spilled over after losing the third set.
Apparently refused a request to leave the court to freshen up, Medvedev barked at the French chair umpire Renaud Lichtenstein and complained that Cressy was spending too much time between serves.
Medvedev's frustration only grew as eight break points slipped through his fingers in the fourth set before he finally slipped a forehand past the American in the 11th game to take his serve.
The 25-year-old world No 2 wrapped up proceedings with a slew of huge serves before stepping in to thrash a forehand winner on match point, completing a 6-2 7-6, 6-7, 7-5 victory in three-and-a-half hours.
"It was long and it was not easy, the scoreline apart from the first set were all tough sets and if I didn't win the fourth set I would have been in a tough mental shape," Medvedev said.
"I had so many break points in the fourth set, I just wanted to make one. I definitely had some break points where I could have played them a little bit better.
"He still gave me the chance to be in that game, but it was a hell of a match."
Last year's finalist and the reigning US Open champion, Medvedev next meets Canada's Felix Auger-Aliassime for a place in the semi-finals. If Medvedev goes all the way and clinches the title - as he is favourite to do - then he will replace Novak Djokovic as world No 1.
Auger-Aliassime had earlier booked his last-eight spot after winning a four-set battle with veteran Marin Cilic.
The Canadian ninth seed downed the 27th seeded Croatian Cilic, who was Australian Open runner-up to Roger Federer in Melbourne in 2018, 2-6, 7-6, 6-2, 7-6 in 3hr 35min on John Cain Arena.
He joins Denis Shapovalov in the quarter-finals to make it the first time two Canadian men have reached that stage at the Australian Open.
"It's amazing. It puts my belief even higher, I lost three times to Marin in the past, this is my first win against him and in an important moment like this," Auger-Aliassime said.
"I told him at the end of the match he's a champion, the way he handles himself and the way he plays and I knew he was going to come out with his best level and test me and make me earn my win.
"So I'm really relieved and happy to get through, especially the way I did it."