A US Open unlike any other finished unlike any other — with an unprecedented fifth-set tiebreaker as Dominic Thiem became the first man in 71 years to win the final after dropping the opening two sets.

So close to defeat in a nearly empty Arthur Ashe Stadium — fans were banned because of the coronavirus pandemic — Thiem slowly but surely turned things around against a faltering Alexander Zverev and pulled out a 2-6, 4-6, 6-4, 6-3, 7-6 (6) victory at Flushing Meadows for his first Grand Slam title.

The match ended with both men fighting leg cramps and, clearly, nerves.

“Somehow,” said Thiem, a 27-year-old from Austria, “the belief today was stronger than the body, and I’m super happy about that.”

When a backhand from Zverev landed wide on the third championship point, a weary Thiem dropped to his back way behind the baseline and covered his face with his hands. When he arose, he was met by Zverev, who walked around the net to clasp hands and then embrace his friend and foe, two sights rarely seen in this era of social distancing.

Thiem then rested his head on the shoulder of the taller Zverev, who himself came within two points of what would have been his first major triumph.

“I wish we could have two winners today,” Thiem said. “I think we both deserved it.”

He is the first man to win the American Grand Slam tournament after trailing 2-0 in sets in the final since Pancho Gonzales did it against Ted Schroeder in 1949 at an event then known as the U.S. Championships and held in Forest Hills.

The event never had been settled by a fifth-set tiebreaker; no major tournament ever had until Novak Djokovic edged Roger Federer that way at Wimbledon in 2019.