Kim Clijsters was courage personified as the defending champion shook off a painful ankle injury and saved four match points to overhaul China's Li Na 4-6 7-6 6-4 and reach the quarter-finals of the Australian Open on Sunday.
The big-hearted Belgian rolled her left ankle at 3-3 in the first set on a scorching day at Rod Laver Arena but rejoined the battle after a lengthy medical time-out with her foot thickly taped.
In a rematch of last year's finalists, 11th seed Clijsters stared at the abyss when 6-2 down in the second set tiebreak but reeled off six points in a row to take the set and spark a rapturous ovation from the stands.
After trailing 4-0 in the decider, the hard-hitting Li recovered to claw back to 5-4 down but Clijsters weathered the challenge to close out the match and keep her hopes alive of a fifth grand slam title in her farewell year on tour.
"It has to be (one of my best comebacks)," Clijsters said red-faced in a courtside interview after raising her arms in triumph to acknowledge the roaring crowd. "I can't believe I won.
"I knew before the match that it was going to be a tough match, physically, mentally.
"It was amazing to get through and to fight and probably not with my best tennis."
French Open champion Li took the first set of last year's final against the Belgian but was once again left crestfallen after missing a golden chance to put her Melbourne Park nemesis away.
After saving three match points, Clijsters appeared to suffer a mental lapse on the fourth when she attempted a speculative drop-shot that bounced up and begged to be put away.
Fifth-seeded Li charged in but her attempted winner was equally inept and allowed Clijsters to poke a lob over her head to save the point.
The Chinese subsequently crumbled under the pressure, spraying two backhand shots to lose the set before her serve collapsed as Clijsters charged 5-1 ahead in the decider.
Li dug deep to break back and took Clijsters to deuce when she was serving for the match, but surrendered the match after netting a backhand.
Clijsters will play the winner of top seed Caroline Wozniacki and former world number one Jelena Jankovic who play in the evening session at Rod Laver Arena.