Andy Murray said his winning return to Grand Slam competition was "emotional" as he proved his physical fitness matched his mental strength by fighting back from two sets down at the US Open.

"Right now I just feel tired," the 33-year-old Briton told BBC Radio 5 Live.

"I didn’t even know how my hip was going to hold up for a five-set match."

Injuries meant the former world number one was playing in the US Open for only the second time in four years.

After losing the opening two sets on Tuesday, he trailed 3-1 and was a break down in the third, before he won two tie-breaks and then broke the 24-year-old Japanese world number 49 late in the deciding set in a match that lasted four hours 39 minutes.

"When I saw the messages from friends and family, it was emotional," added the Scot, who will play Canada’s 15th seed Felix Auger-Aliassime in Thursday’s second round.

"The fact I got through a five-set match is brilliant and another tick for the metal hip. I don’t want to play too many more of them but it’s good to know it can last.

"I was very close to going out but kept coming back, kept fighting so I'm proud of that. The biggest question would've been the physical one and that was the thing I was most happy with - that I lasted."

A win in front of familiar faces

Murray’s match – his first in the singles at a Grand Slam since losing in five sets to Spain's Roberto Bautista Agut at the Australian Open in January 2019 – was played on Arthur Ashe Stadium with no fans present because of the coronavirus pandemic.

The stadium – the biggest tennis arena in the world – is hosting many of the world’s top players, who are using corporate boxes overlooking the court.

As a result, Dominic Thiem, Stefanos Tsitsipas and Alexander Zverev were among the interested onlookers along with fellow Briton Kyle Edmund and Murray's brother Jamie.

"Everyone you look up at is a coach or a top player," said Murray. "By the end of the match there were a lot of players who came to watch.

"It’s a little odd playing in front of lots of top players because it’s very rarely the case. Usually it’s just the fans and the players are watching on TV. It certainly created more of an atmosphere than there was at the beginning."

Along with Murray, three other British men are in the second round.

British number one Dan Evans will play on Thursday, while Kyle Edmund and Cameron Norrie are in action on Wednesday.

Edmund faces the tougher test of the two, with the 25-year-old playing top seed Novak Djokovic on Arthur Ashe at around 18:30 BST.

Djokovic swept aside Damir Dzumhur in straight sets in the first round as he looks to claim his 18th Grand Slam title.

While Edmund is seeking an upset, Norrie has already secured one. The 25-year-old beat ninth seed Diego Schwartzman in a five-set epic on Monday.

Norrie, ranked 76th in the world, faces a less tricky task in Argentina's world number 103 Federico Coria on Wednesday. That match is expected to begin at around 20:00 BST.

Analysis

Judy Murray, former British Fed Cup coach and Andy’s mother, on BBC Radio 5 Live

Everything is a bonus for Andy from here but because he has such high expectations of himself he's never coming in here to make up the numbers. Even though it is early days and he's testing himself.

This is all a test. It's testing out his body. To come through four hours and 39 minutes is a massive positive.

At two sets down he looked subdued and flat which is so unlike him. But you can never write him off.

When you think what he's been through and the length of the match I was hoping his body could hold up.