Top seed Novak Djokovic overcame stern resistance from Aslan Karatsev to reach the Australian Open final and end the Russian qualifier’s remarkable run.
Despite the world number 114 causing moments of tension, Djokovic had enough quality to win 6-3 6-4 6-2.
The 33-year-old Serb won the final four games to finally shrug off Karatsev.
Djokovic, who is going for a record-extending ninth men’s title in Melbourne, will face Daniil Medvedev or Stefanos Tsitsipas in Sunday’s final.
Russian fourth seed Medvedev meets Greek fifth seed Tsitsipas in the other semi-final on Friday, with both men trying to reach their first Australian Open final.
Neither player has won a major title yet and will face an opponent in Djokovic who is bidding for an 18th Grand Slam to close the gap on Roger Federer and Rafael Nadal.
Djokovic has struggled with an abdominal injury during the tournament but showed no signs of the problem against Karatsev.
“This is the best I have felt in the entire tournament. It felt great, I could swing through the ball and no pain,” he said.
“It was my best match so far and came at the right time. I’m thrilled.”
Tense Djokovic digs deep to see off Karatsev
Nobody has mastered the Australian Open men’s singles like Djokovic, who says the event “feels like home” after dominating the tournament since winning his maiden title in 2008.
Djokovic has lost only three matches at Melbourne Park over the past decade and losing to Karatsev would have been a seismic shock ranked among the sport’s great upsets.
While Djokovic was playing in his 39th Grand Slam semi-final, Karatsev had never even played in one of tennis’ four major tournaments before this fortnight.
There was a piece of history, however, which offered hope to the Russian. Djokovic had lost to an opponent ranked as low as Karatsev once before on Rod Laver Arena – when he fell to Uzbekistan’s world number 117 Denis Istomin in the second round in 2017.
While Karatsev pushed Djokovic and worried him at times with powerful hitting, a repeat never seriously looked like happening.
Little separated the pair as they stayed on serve in the opening seven games, before a loose eighth game from the Russian allowed Djokovic to pounce for 5-3 and then serve out to love for the first set.
Fears the match would quickly run away from Karatsev looked justified when Djokovic opened up a 5-1 lead in the second. But Karatsev, like he had throughout the tournament, hung in.
After clawing one of the breaks back, Karatsev saved two set points as Djokovic tried to serve out again – and, to the pleasure of the Melbourne crowd allowed back in to watch, threatened to break again to level.
Djokovic looked pensive as he was forced to dig deep, letting out an explosion of emotion as he eventually got over the line to take a two-set lead.
Yet again, the third set did not prove to be the procession which Djokovic might have hoped.
Karatsev rallied to wipe out an early break of serve before Djokovic, still looking tense, reasserted his control as the Russian tired.
Djokovic sealed victory with an ace down the middle, baring his teeth and clenching his fist as a steely celebration indicated his relief.
Dogged display ends remarkable fortnight for Karatsev
Karatsev’s run to the last four in Melbourne is one of the most remarkable stories in the men’s game in recent years.
Few outside of the tennis world had heard of the 27-year-old, who has largely plied his trade on the second-tier ATP Challenger Tour, before he became the first man in the Open era to reach the semi-finals on his Grand Slam debut.
Even Djokovic admitted before Thursday’s semi-final he had not seen Karatsev play until this fortnight. He quickly became acquainted with the Russian’s explosive power.
There were few signs of nerves from Karatsev despite being on the biggest stage of his career, while he also showed his mental resilience by refusing to wilt and pegging Djokovic back in the final two sets.
The Russian looked exhausted as he limped off court and received a standing ovation, which also saw Djokovic join in, to celebrate the scale of his achievements.
As well as more than doubling his career earnings with the £475,000 prize money, Karatsev will climb into the world’s top 50 when the rankings are released on Monday.
He said the experience of the past fortnight, having had to win three qualifying matches to reach the main draw, will provide him with the confidence that he can regularly compete with the world’s best players.
Asked what he has learned, Karatsev said: “That I can play with everyone. To be there and to compete with everyone.
“It was a great two weeks for me and to play against Novak, it helps me to get this experience, to feel the game, the way how he’s playing.
“I’ll get this confidence and just keep playing, keep practising.”