NEW YORK (REUTERS/AFP) - Dominic Thiem produced a remarkable fightback to beat German fifth seed Alexander Zverev 2-6 4-6 6-4 6-3 7-6 (6) to win the US Open for the first time on Sunday (Sept 13).

The second seed became the first Austrian to claim a singles title at Flushing Meadows, albeit in unique circumstances as no fans were present at the hardcourt major due to the Covid-19 pandemic.

The 4hr 2min match inside a near-empty Arthur Ashe Stadium marked the first time in the US Open's Open Era history that a player had recovered from losing the opening two sets to win the title.

It was also the first time the final had been settled by a tie-break.

The title marks Thiem's maiden Grand Slam trophy after three previous defeats in finals of tennis majors.

"It's amazing how far our journeys brought us to share this moment and I wish - really I wish - we could have two winners today, I think we both deserved it," Thiem said on court after a tearful speech from his crestfallen opponent and close friend.

"It's going to be or I expect that it's going to be easier for me now in the biggest tournaments," Thiem told reporters.

"Because, of course, I had it in the back of my head that I had a great career so far, way better career than I could ever dreamt of, but until today there was still a big part, a big goal missing.

"With this goal achieved, I think and I hope that I'm going to be a little bit more relaxed and play a little bit more freely at the biggest events," he added.

Zverev cried as he tried to thank his parents Alexander - also his coach - and Irina who were not in New York after testing positive for coronavirus.

"I miss them. I'm sure they are sitting at home pretty proud even though I lost. I wish one day I can bring the trophy home," he said.

Thiem was runner-up at the Australian Open earlier this year and also lost in the last-two showdowns at the French Open in 2018 and 2019.

He also becomes the first new Grand Slam champion since Croatian Marin Cilic won at Flushing Meadows in 2014.

Thiem is also the first Grand Slam champion other than Novak Djokovic, Rafael Nadal or Roger Federer since Switzerland's Stan Wawrinka won the third of his majors at the 2016 US Open.

Zverev smashed four aces and 16 winners in the first set as he displayed an impressive serve and volley game to take a 1-0 lead in just 30 minutes.

The German was helped by some sloppy serving from Thiem, who hit three double faults as he was broken twice, in games three and seven.

In set two, Zverev wasted three set points while 5-1 up but held on to take a 2-0 lead on his fifth set point.

The tide was beginning to turn though as Zverev's play became increasingly cagey as his suspect second serve got slower and his forehand, another weakness, became more defensive.

After Thiem easily took set four, Zverev found himself serving for the championship at 5-3 in the fifth set.

But he could not hold and soon Thiem found himself 6-5 ahead. He took a medical timeout before it was his turn to serve for the championship.

However, like Zverev moments earlier, Thiem failed to clinch the match and it went to a tie-break.

He found himself 5-3 up after two double faults by Zverev but Thiem, by now exhausted and limping, blew two championship points.

He won the title on his third and collapsed to the court with his head in his hands.

"Honestly, I think it didn't help me at all because I was so tight in the beginning," he explained.

"I mean, I wanted this title so much, and of course there was also in my head that if I lose this one, it's 0-4.

"It's always in your head. Is this chance ever coming back again? All these thoughts, which are not great to play your best tennis, to play free," he added

Thiem said lifting the US Open was a dream come true.

"I achieved a life goal, a dream of myself, which I had for many, many years. Of course, as a kid, as well, when I started to play tennis. But back then it's so far away," he told reporters.

"Then I got closer and closer to the top. At one point I realized that, 'Wow, maybe one day I can really win one of the four biggest titles in tennis.'

"I put a lot of work in. I dedicated basically my whole life until this point to win one of the four majors. Now I did it. That's also for myself a great accomplishment."

The match was watched by just a few dozen people, mostly officials, journalists and event staff after the coronavirus pandemic forced the tournament to be held behind closed doors.

This year's field at the Billie Jean King US National Tennis Center in New York was depleted by the absence of Swiss legend Federer and defending champion Nadal.

The tournament was also blown wide open by the disqualification of world No. 1 and heavy favorite Djokovic in the last 16 for hitting a line judge with the ball.