Rafael Nadal moved one win away from a record 21st Grand Slam men's title after a dominant start enabled him to beat Italy's Matteo Berrettini in the Australian Open semi-finals.
Seventh seed Berrettini eventually turned the match into a contest, but Nadal completed a 6-3 6-2 3-6 6-3 win.
The 35-year-old Spaniard is level on 20 major titles with long-time rivals Novak Djokovic and Roger Federer.
Nadal will face Daniil Medvedev or Stefanos Tsitsipas in Sunday's final.
"The first two sets were some of the best I've played for a long time," said Nadal, who won his only Melbourne title in 2009.
"I had to suffer and I had to fight but to be in the final again means a lot."
Nadal's achievement in reaching a 29th Grand Slam final comes only a few months after he thought a foot injury could end his illustrious career.
Russian second seed Medvedev plays Greek fourth seed Tsitsipas later on Friday in the second men's semi-final at Melbourne Park.
It is the first time both men's semi-finals have been played on the same day since 1999, after the decision by tournament organisers to put both women's semi-finals in the primetime Thursday night session.
US Open champion Medvedev, 25, was beaten in last year's final by Djokovic, who did not play this year after being deported from Australia in a visa row related to him being unvaccinated.
Tsitsipas, 23, is targeting his maiden Grand Slam title - after losing to Djokovic in last year's French Open final - and his first Melbourne final.
Before the match there were some lingering doubts about Nadal's chances, not least because of his injury problems last year.
These centred around the indoor conditions perhaps favouring the powerful Berrettini - severe thunderstorms in Melbourne meant the roof was closed throughout - and how 35-year-old Nadal would have recovered after being "destroyed physically" from a gruelling five-set quarter-final against Canada's Denis Shapovalov.
With the benefit of two full days without a match since Tuesday's win, Nadal quickly quashed any uncertainty.
Nadal started sharply as he attacked Berrettini's backhand - considered the weakest part of the 25-year-old Italian's game - from the outset.
A stream of mistakes came from this side as Berrettini fell 3-0 behind and Nadal appropriately sealed the opening set with a serve to the backhand, which the 2021 Wimbledon finalist returned into the net.
This Berrettini shot continued to break down in the second set, enabling Nadal to take his opening two service games and move into another 3-0 lead.
Head bowed, Berrettini looked unsure how to neutralise Nadal and the other facets of his game were suffering too.
When Nadal sealed the second set after one hour and 25 minutes, Berrettini had already hit 24 unforced errors. His inability to test Nadal - in part because of the Spaniard's brilliance - had been costly.
Berrettini won 23 straight points from the midway through the third set to when Nadal broke for 5-3 in the fourth
Holding serve at the start of the third set, and putting scoreboard-pressure on Nadal, was imperative for Berrettini.
Once he achieved that, the Italian's confidence grew and his fearsome forehand began to trouble Nadal more.
Finally he earned his first break points of the match, taking the second for a 5-3 lead with another forehand winner and serving out to love to ensure at least a fourth set.
Both men held serve in the opening seven games but Berrettini letting half a chance slip from 3-3 15-30 with two missed forehands proved crucial.
Berrettini had held to love in five successive service games - but then let Nadal in when it mattered most.
After Nadal missed a first break point with a wide forehand to end an intense 23-shot rally, Berrettini hit a forehand into the net for the third time in the game on the second.
Serving for the match, Nadal started with a double fault but clinched victory when Berrettini put another backhand into the net.