Stefanos Tsitsipas overcame a third-set wobble to defeat Karen Khachanov and reach his first Australian Open final.
The third seed has been a man on a mission all fortnight, troubled only by Jannik Sinner in the fourth round until now, and he looked set to cruise into the final as he stepped up to serve for a straight-sets victory.
But Russian Khachanov clung on, breaking Tsitsipas and then saving two match points in the third-set tie-break before the Greek eventually clinched a 7-6 (1) 6-4 6-7 (6) 6-3 victory.
Tsitsipas had reached the last four in three of the last four years at Melbourne Park without going further, losing in 2019 to Rafael Nadal and in 2021 and 2022 to Daniil Medvedev.
He was not to be denied this time, though, and will now aim to go one better than his only previous slam final at the French Open in 2021, when he led Novak Djokovic by two sets to one but was eventually beaten.
He may well find the Serbian on the other side of the net again but will believe, if he can show the same form he produced for most of this contest, he can have a chance of pulling off the upset.
Tsitsipas will surely need to avoid the same lapses if it is Djokovic he faces, though, after also failing to serve out the opening set.
Having broken to lead 5-3, Tsitsipas played a poor game to drop serve and was then briefly in trouble at 5-5 after double-faulting when a second time violation resulted in him forfeiting a first serve.
He recovered to hold, though, and played a flawless tie-break to move in front.
Tsitsipas, who had won all his previous five matches against Khachanov, was the better player in the second set as well, finally breaking in the penultimate game, and he appeared poised for victory serving for the match at 5-4 in the third.
Khachanov rallied, though, breaking back and then producing two huge forehand winners when Tsitsipas moved 6-4 ahead in the tie-break.
The third seed appeared rattled and drove a forehand long to hand the set to Khachanov, but he regrouped quickly with a break at the start of the fourth and this time held onto it.
The result means a second successive semi-final exit at a slam for Khachanov, who was cheered on by a number of fans waving Armenian flags following his public support for the breakaway region of Artsakh.