Lleyton Hewitt overcame a hip injury to beat Spain's Rafael Nadal 7-5 3-6 1-6 7-6 (7-3) 6-2 and keep his dream of winning the Australian Open alive.
The third seed looked to be on the brink of defeat when 18-year-old Nadal clinched the third set with ease after Hewitt had treatment for the problem.
But the Australian raised his game in the fourth and took it on a tiebreak.
Roared on by the crowd, Hewitt raced through the decider to reach the last eight for the first time in his career.
Losing the fourth set visibly deflated Hewitt's unseeded opponent and it was then Nadal's turn to receive treatment on his left thigh.
But it was merely delaying the inevitable as Hewitt raced into a 3-0 lead in the decider with two breaks of serve.
The home hero then went on to wrap the match up in three hours 53 minutes to set up a quarter-final match with David Nalbandian, who powered past fellow Argentinian Guillermo Coria 5-7 7-5 6-3 6-0.
But, despite his dominance in the latter stages, Hewitt admitted he had been given a tough test by the Spanish teenager - a player he rates highly.
"I was hurting a little bit but told myself to hang in there," said the 23-year-old.
"I strained my hip flexor in Sydney last week but I will be fine.
"Nadal's got a great attitude for tennis - he is hungry and good for the game. He's gonna be around for a while."
Nadal set his sights on a place in the world's top 20 after pushing Hewitt to the limit.
"I am happy because I played a good match and I had a lot of chances for a win," he said.
"I am happy because he is number three in the world and I played the same as him. If I play at this level, I can do important things this year."
Nalbandian, who lost to Hewitt in the 2002 Wimbledon final, got off to rocky start against Coria.
Sixth seed Coria had treatment on a groin injury early on, but it did not seem to affect his game as he came from a break down to win the first set.
But as the match progressed, ninth seed Nalbandian found his range and pace and eventually his greater weight of shot told.