"Built Belgian tough" might become a badge of honour for future tennis generations after courageous Kim Clijsters' win over Li Na on Sunday, while Roger Federer dashed the dreams of home fans by crushing young gun Bernard Tomic.
On a day when the clouds cleared, the mercury bubbled and temperatures soared, Rafa Nadal won a battle of Spanish lefties against Davis Cup team mate Feliciano Lopez, and Tomas Berdych was booed mercilessly for a petulant show of bad sportsmanship.
Defending champion Clijsters crumpled to the court at 3-3 in the first set after her left ankle rolled sickeningly over.
The Belgian, bidding farewell to the Australian Open in the final year of her career, hauled herself to her feet, and after she lost the point hobbled to her seat for treatment.
Grimacing in pain with a heavily strapped ankle she limped back to court to serve out the game, but Li took advantage of her opponent's lack of mobility to win the first set.
The 28-year-old Belgian clawed her way back into the match to win the second in a tiebreak as the crowd began to believe she could gut out the win.
Clijsters closed out the match 4-6 7-6 6-4 to keep her hopes alive of a fifth grand slam title but conceded the injury had made her think about retiring against Li, whom she beat in the 2011 Melbourne Park final.
"It definitely crossed my mind at some point, but I knew if I could just try to let the medication sink in, get through the first 20 minutes ... the pain would go away a little bit and maybe with the adrenaline I could just fly through it," she said.
Anyone tuning in late to the game would never have guessed Clijsters was injured as she chased, jumped and did the splits.
"I felt it throughout the whole match, it's not something that goes away," she added. "But I did feel a difference when the medication kicked through ... definitely the throbbing went away."
Clijsters was joined in the quarter-finals by number three seed Victoria Azarenka, who endured her traditional late-game hiccup before beating Iveta Benesova 6-2 6-2.
World number one Caroline Wozniacki and Jelena Jankovic are also battling for a berth in the last eight on Sunday.
Still giddy from Lleyton Hewitt's late-night heroics against Milos Raonic, Australian fans could barely believe they had two players in the fourth round but hopes that 19-year-old Tomic could depose four-times champion Federer proved wide of the mark.
Teen Tomic had already come through two five-setters to reach the fourth round while 30-year-old Federer looked as fresh as a daisy in securing a 6-4 6-2 6-2 win.
The Swiss, bidding to match Roy Emerson's record of five Australian Open titles, will face former U.S. Open champion Juan Martin Del Potro in the quarter-finals.
World number two Nadal, with heavy strapping on knee, ankle and foot, huffed and puffed his way past Lopez with little Spanish sparkle but was happy to go no more than three sets.
Memories of his last eight withdrawal against Andy Murray two years ago, and defeat at the hands of David Ferrer last year, still haunt him.
"Hopefully it won't happen this time," said Nadal after his 6-4 6-4 6-2 win. "Every year is different. I had a bad experience for the last two years here. It's tough to have to go out of a tournament like Australia in quarter-finals.
"In 2010 I retired because I couldn't continue. Last year I decided not to retire but I had a problem in the second or third game of the match. So I played one complete match with very bad feelings."
In the day's only real note of controversy, Czech Berdych was booed off Hisense Arena after a bad tempered 4-6 7-6 7-6 7-6 win over Nicolas Almagro.
Berdych refused to shake hands with the Spaniard after he sealed the win because he felt the 10th-seeded Almagro had deliberately blasted a return at his head during the fourth set.
"The court is pretty big and you always have some space to put the ball in," number seven Berdych complained. "And not even if you are standing three or four metres from the guy (does he need) to hit it straight to your face.
"This is not the way how tennis is."
The ball hit Berdych's arm and while the Spaniard apologised immediately, the Czech was still incensed at the conclusion of the match.
Berdych's courtside interview was drowned out by the crowd booing and hissing, while tennis coach and commentator Brad Gilbert said he was appalled at the Czech's decision.