Rafael Nadal suffered a remarkable collapse to exit the Australian Open at the quarter-final stage despite earlier leading Stefanos Tsitsipas by two sets. (More Sports News)
Only once in Nadal's grand slam career had he previously let a two-set lead slip and such a slump appeared entirely improbable as he dominated Tsitsipas on Rod Laver Arena.
But the 20-time major champion, chasing a record-breaking 21st title, struggled to recover his momentum after dropping a set for the first time in the tournament when the third went to a tie-break.
The courageous Tsitsipas grew in confidence and landed a momentous second career win over Nadal to reach a third slam semi after a four-hour 3-6 2-6 7-6 (7-4) 6-4 7-5 epic.
A back issue had hampered Nadal at the start of the tournament, but his progress thereafter - up until the third set on Wednesday - was serene.
While Daniil Medvedev, the last-four opponent in waiting, queried what would happen to Nadal "if somebody pushes him to a five-hour match", Tsitsipas appeared unlikely to provide such a test when a backhand return beat his attempted serve and volley to forge a first break point in the eighth game of the opener.
Tsitsipas went long, allowing Nadal to serve out the set, and was swiftly on the back foot again when a sweeping backhand teed up another opening, which was taken once more.
A superb forehand left Tsitispas marooned on the opposite side of the court, a theme that continued as Nadal blasted past his opponent at the net for another break opportunity, quickly converted en route to wrapping up a rapid second set.
However, improved serving from the Greek in the third took Nadal to a tie-break, where a wild, wayward volley and another missed overhead gifted Tsitsipas the set and a foothold.
Emboldened by that unexpected boost, Tsitsipas applied pressure for the first time and, although three opportunities initially came and went, he broke for the first time at the end of a second consecutive Nadal service game of more than seven minutes.
A steely hold set up the decider and Tsitsipas was not about to let the opportunity pass, dictating the play and breaking again to love, before clinching victory despite a late show of nerves as Nadal went down fighting.