Britain's Andy Murray reached his fifth Australian Open final by winning an epic five-set battle with 13th seed Milos Raonic.
World number two Murray was broken in the first game of the match and his 25-year-old Canadian opponent went on to take the first and third sets.
But the 28-year-old Scot prevailed 4-6 7-5 6-7 (4-7) 6-4 6-2 in a gruelling four-hour contest.
Murray will meet defending champion Novak Djokovic in Sunday's final.
"It was tough in that third set. In the tie-break he didn't miss a single serve and it is frustrating when you don't get a say in the points," said Murray, who has been a runner-up in the tournament four times.
"Over the match, I got a better read on his serve and that was crucial."
The result means Murray and older sibling Jamie are the first brothers in the Open era to reach the finals in both the men's singles and men's doubles events at a Grand Slam.
Jamie Murray and Bruno Soares will play Daniel Nestor and Radek Stepanek in the doubles final on Saturday.
The Murrays' fellow Scot Gordon Reid is on course for an Australian Open double after reaching the final of the men's wheelchair in both the singles and doubles.
Much has been made of distraction off court for Murray during this tournament, with wife Kim heavily pregnant at home in Britain, and her father Nigel recovering from illness.
The Scot had come through the first five rounds relatively unscathed but made the worst possible start to his sixth Australian Open semi-final, as Raonic went on the hunt for a place in his first Grand Slam final.
The 6ft 5in Raonic stunned Murray by breaking him in the first game and the Briton failed to execute three break points on the Canadian's serve as he fell 2-0 behind.
Raonic, who was unbeaten in 2016 having won the Brisbane Open earlier this month, was then able to rely on his trademark big serve to see out the first set without much drama.
Raonic broke his racquet in frustration during his four-hour contest with Murray
Raonic held off two breaks but rarely threatened on his opponent's serve, and Murray's patience was rewarded as he took the second set 7-5.
After five games were won to love in the third set, it became a matter of who was going to crack first.
A tie-break followed, and big-serving Raonic was in his element. He raced into a three-point lead and, with two set points, he won it with his 13th ace of the match.
But Murray's confidence was not affected and he made sure he took the match all the way by breaking late in the fourth to take it 6-4.
Raonic looked to be struggling through injury and fatigue, and called for a medical time-out before the start of the fifth. As the Canadian tired, Murray seemed to get stronger and he took the final set with ease.
"He definitely slowed down in the fifth set for sure which was unfortunate for him," the Scot said of Raonic's injury.
"I obviously got a bit lucky on that but you just try to focus on your side of the court."
Raonic said: "That's probably the most heartbroken I felt on court, but that's what it is."
BBC tennis correspondent Russell Fuller
Raonic came out of the blocks like Novak Djokovic: breaking Murray to love in the opening game and tormenting him with serves to the body at 140mph.
The leg injury which denied the Canadian the chance to make the deciding set truly competitive was cruel on someone who had played so magnificently, yet Murray had been his equal throughout. He actually won a higher percentage of first-serve points than Raonic, and won two out of every three points on his much maligned second serve.
Murray also kept his emotions much more in check than he was able to earlier in the week: he will need a repeat performance come Sunday's final.
Former Wimbledon champion Pat Cash: "This match won't have taken an awful lot out of Murray - the rallies weren't that long. He was moving very well at the end and was playing confidently. He knows where he failed in last year's final against Djokovic. He knows he must keep the pressure up and can't afford any lapses.
"Last year he was at himself the whole time. He shouldn't have been but he couldn't stop himself and for his sake I'm hoping he has learnt the lessons from that and can control his emotions."
BBC tennis correspondent Russell Fuller: "Maybe last year Murray didn't believe he could beat Djokovic, but now he's more confident in his abilities and Djokovic has been a bit off-key at times, making 100 errors in his match against Gilles Simon."