Sebastian Korda has secured easy passage to the Adelaide International men's final after Yoshihito Nishioka retired hurt midway through their semi-final clash.
He'll meet Novak Djokovic in the decider after the Serb downed Daniil Medvedev 6-3 6-4 in the other semi-final.
Nishioka had a second meltdown in as many days, frustrated when a crucial point during the first-set tiebreak on Saturday had to be replayed because of an error by a line judge.
Korda won the replayed point to claim the set as Nishioka blew up, venting his frustration at chair umpire Simon Cannavan.
"You never been in tennis. You don't know what is important point," Nishioka moaned from his seat.
Korda broke Nishioka's serve in the opening game of the second set and the Japanese left-hander called a medical timeout for treatment on an apparent leg injury.
Nishioka returned to play a few more points but retired mid-game, with the American leading 7-6 (7-5) 1-0.
"It was a very tough match," Korda said.
"We were both battling on each other's serve but there was a crucial tiebreaker and (it was) unfortunate the way it ended, but I'm still very happy."
It was Korda's third win in as many attempts against Nishioka.
The 22-year-old lost his two most recent of four previous ATP finals last October, to top-10 stars Andrey Rublev and Felix Auger-Aliassime in Gijon and Antwerp respectively.
Regardless of whether he wins the Adelaide final, Korda's performance in South Australia will improve his ranking and guarantee he is seeded at this month's Australian Open.
"You don't have to face a top speed in potentially the first round. It's really big," Korda said.
"I've only been seeded one before, actually played (Carlos) Alcaraz in the third round.
"It's pretty cool to come back to my second Aussie Open and be seeded. A lot of positives this week. I'm excited."
Korda, who won the 2018 Australian Open boys title, is the son of former Australian Open champion Petr Korda.
His older sisters Jessica and Nelly Korda are both former women's Australian Open golf champions.