Carlos Alcaraz saved a match point then turned around a tiebreaker to beat Hubert Hurkacz 2-6, 7-6 (7/4), 6-3 and reach the final of the ATP Cincinnati Open on Saturday.
The world number one rallied to beat the big-serving Pole for the second time in as many weeks, dominating the third set to line up a title clash against either Novak Djokovic or Alexander Zverev.
The victory, after two hours and 18 minutes, was the 20-year-old Spaniard's 53rd match win of the season against five defeats.
On Sunday he'll be seeking his seventh title of 2023.
The win ensures he will remain atop the world rankings heading into the US Open, which starts a week from Monday.
"It's been a really tough tournament for me, all my matches going three sets," Alcaraz said. "But I'm happy to win these kind of matches by staying strong mentally.
"I've grown up a lot with these experiences. It's great to be in the final," he said.
After dropping the first set, Alcaraz was on the brink in the 10th game of the second, but Hurkacz fired wide on a match point and they went to a tiebreaker.
Hurkacz took a 4-1 lead in the decider, but Alcaraz stormed back to square the match, converting the first of two set points.
In the third, an Alcaraz break for 3-1 proved to be decisive and the youngster advanced on a drop volley winner.
"It was a mental battle, I had to stay present and positive all the time," he said. "I knew I would have chances, I just had to take them. I'm happy I was able to win it."
Alcaraz will aim for his third Masters trophy of the season after Indian Wells and Madrid. Cincinnati will be his eighth final of 2023.
He is the youngest Cincy finalist since a 19-year-old Pete Sampras in 1991.
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