The win gives Thiem his first career Grand Slam victory after three previous finals appearances.
Dominic Thiem beat Alexander Zverev in five sets 2–6, 4-6, 6–4, 6–3, 6-6 (8-6) to win his first U.S. Open title on Sunday.
The victory was Thiem's first Grand Slam championship after making three previous Slam final appearances.
Thiem dropped the first two sets and had 21 unforced errors before staging his comeback. He was particularly sharp in the fourth set, winning all 12 of his second serves with only two unforced errors.
Zverev led, 5-3, in the fifth with a chance to serve for the win but was unable to close it out. Thiem took the next set with back-to-back winners, drawing level at 5-5. Thiem then broke Zverev's service to take a 6-5 lead before serving for the championship, though he was broken after receiving medical attention for some discomfort in his legs.
That forced a tiebreaker, in which the two split the first six points before Thiem took a 5-3 lead on an ace and a double fault by Zverev. After falling behind, 6-4, Zverev broke Thiem's serve and then drew level, 6-6, thanks to a pair of unforced errors by Thiem. Thiem then won the next two points to win the tiebreaker, 8-6, and clinch the championship.
In the fifth set, Thiem hit 14 winners and covered an average of 68.5 feet per point, both his most of any set in the match.
Thiem, 27, last appeared in a Grand Slam final in this year's Australian Open, losing in five sets to Novak Djokovic. He made the French Open final in 2018 and 2019, losing each time to Rafael Nadal. Prior to this year, the furthest he had advanced in the U.S. Open was the quarterfinals in 2018.
Zverev, 23, had never reached the semifinals of a Grand Slam before this year's Australian Open, when he was defeated by Thiem in four sets. His previous best finish at the U.S. Open was a fourth-round appearance in 2019, when he lost to Diego Schwartzman.