Dominic Thiem
Thiem ousted Kei Nishikori in his fourth-round match on Sunday.THOMAS SAMSON/AFP/Getty Images

Second-seeded Dominic Thiem overcame a left ankle injury to enter his first US Open final, beating Daniil Medvedev in a pulsating semi-final clash at the Arthur Ashe Stadium.

On Friday evening, Thiem displayed his trademark fighting spirit to beat third-seeded Medvedev 6-2, 7-6(7), 7-6(5) in a match that lasted almost three hours. He will play No. 4 Alexander Zverev of Germany in Sunday's final. Each is looking for his first major win.

US Open men's final to see Thiem and Zverev fight it out

"After the first set, it could easily have been two-sets-to-one down," Thiem said after the match as per the official tournament website. "I played my best tennis at the ends of the sets and both tiebreaks were amazing. Tiebreaks are really mentally a tough thing."

"I don't like them at all, to be honest," he added.

Earlier, Zverev made it to his first Grand Slam final, dismissing Pablo Carreno Busta, 3-6, 2-6, 6-3, 6-4, 6-3 in three and a half hours to advance to the championship round of the tournament.

"Even though I was down two sets to love, I stayed in it," Zverev said of his mental toughness after the match. "I gave myself the best chance I could. I think a lot of players would have gone away. Today I dug deep, dug very deep. At the end of the day, I'm sitting here as the winner of that match, which could have been very different."