Novak Djokovic retired injured from his Australian Open semi-final against Alexander Zverev on Friday and left the court to boos, with defending champion Jannik Sinner to face the German for the title.
Top-ranked Sinner blew past Ben Shelton 7-6 (7/2), 6-2, 6-2 despite some late cramp in the second semi-final in Melbourne to set up a meeting between the Italian and second seed Zverev.
The Rod Laver Arena crowd jeered Djokovic, who played with a heavily taped leg, when he called it a day after losing a gruelling first set against Zverev, leaving his bid for a record 25th Grand Slam crown in tatters.
The 37-year-old Serbian great shook hands after going down 7-6 (7/5) and said he had been hampered by a muscle tear.
Djokovic, the last of the "Big Three" following the retirements of Rafael Nadal and Roger Federer, hinted that he may have played his last Australian Open.
"There is a chance. Who knows?" Djokovic said when asked if he may have graced for the last time the Melbourne Park courts where he is a 10-time champion.
"I normally like to come to Australia to play. I've had the biggest success in my career here. So if I'm fit, healthy, motivated, I don't see a reason why I wouldn't come," he added.
Djokovic has now gone five Grand Slams without winning the title he needs to surpass Margaret Court's 24 and become the all-time leader.
In the other semi-final, Sinner had to save two set points in a tight opening act that lasted a marathon 71 minutes and he suffered in the latter stages after long rallies against his high-octane American opponent.
"I had some tension today, slightly cramps," Sinner admitted.
"But he was also suffering today a little bit in his legs."
Once Sinner grittily snared the opening set on a tiebreak he took only another 85 minutes to win the next two sets against 22-year-old Shelton.
"For three sets, two and a half hours is quite a time. So happy to finish today in three," the Italian said.
"But, you know, as I said, I'm very happy to be back in the finals and then we see what is coming Sunday."
- 'Stop blaming Novak' -
Djokovic had been ominously warming to the task before he suffered a leg muscle tear during his victory over Carlos Alcaraz in the quarter-finals.
"I actually thought I played really well, as well as I played the last 12 months," he said of his run at the first major of the year, where he had old rival Andy Murray in his coaching corner for the first time.
"I liked my chances if I was physically fit and ready to battle."
Zverev leapt to the defence of the Serb after some in the crowd made clear their feelings about his premature exit.
"I think we should stop blaming Novak," he said.
"Novak has done absolutely everything he could on the tennis court in the last 20 years," he added.
Sinner is on the cusp of a first successful Grand Slam title defence after winning his maiden major crown in Melbourne last year.
He had won the last four of his five career meetings with Shelton.
The Italian was not at his best in the opening set, dropping his serve twice and having to dig deep to save two set points with Shelton serving at 6-5.
But the 23-year-old easily took control of the tiebreak to move a set ahead.
He broke Shelton right at the start of the second and ran away with it.
The American roused himself for one last effort in the third, lashing running forehand winners in an attempt to turn the tide.
Sinner was not moving freely by now, but he saved two break points and when Shelton then dropped his serve to go 3-2 down, the Italian upped the ante and sprinted to the finish line.
Sunday's final will be a battle of the top two seeds with Zverev in his first Australian Open final.
The German has been a Grand Slam runner-up twice before, at last year's French Open and the 2020 US Open, but has never lifted one of the big four majors.
By Martin Parry