Use audio icon at top of page to listen to BBC Radio 5 Live Sports Extra commentary (UK only)
Stefanos Tsitsipas beats Andy Murray 6-2 6-7 (7-9) 6-3 3-6 6-4 on Arthur Ashe in first round
British number one Dan Evans beats Brazil's Thiago Monteiro 6-3 6-7 (6-8) 6-4 6-1
Britain's Heather Watson and Harriet Dart make first-round exits
British number one Johanna Konta pulls out of tournament hours before her scheduled first-round match
Later: Cameron Norrie v Spain's Carlos Alcaraz
*Murray 6-2 6-7 (7-9) 3-1 Tsitsipas
It is hard to get your head around the fact that Andy Murray has only got the single pair of shoes available to him on Arthur Ashe today, even just in case of malfunction.
They're not bothering him too much in this set so far, however, but Tsitsipas is on the board in set three. A hold to love makes it 3-1.
Russell Fuller
Tennis commentator on BBC Radio 5 Live
Murray has been wringing out his shoes wherever possible.
It is horribly sweaty in New York and he has only brought one pair of shoes to the court.
Laura Robson
Former British number one on BBC Radio 5 Live
I thought Andy would be the one to have a lull after the highs and lows of set two.
He's so strong mentally time and time again. He looks like he's really in control of his emotions today.
Murray 6-2 6-7 (7-9) 3-0 Tsitsipas*
Murray cruises to 40-0 on serve as he looks to consolidate his advantage, and after sending one long he does just that to take a 3-0 lead in the third set. What a start!
#bbctennis
Jiiten Chandarana: Can someone please find a pair of tennis shoes and deliver it to Ashe ASAP? Thanks.
Laura Robson
Former British number one on BBC Radio 5 Live
I'll be the first one to say how wrong my prediction was for today.
Andy came out absolutely firing. His movement is the best I've seen in a very long time. It makes such a difference for him mentally.
He believes he's able to win these matches. He's been telling us that for so long.
*Murray 6-2 6-7 (7-9) 2-0 Tsitsipas
Break point, taken!
There's no sign Andy Murray is slowing down anytime soon in this match. He makes the perfect start to the third set.
Murray 6-2 6-7 (7-9) 1-0 Tsitsipas*
A solid serve for Stefanos Tsitsipas to start the game is followed by a double fault, and Murray again draws level at 30-30 as the Greek is beaten at the net.
And a first break point chance of the third set falls the Briton's way...
Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra
I think that set was must-win for Andy.
Tsitsipas was under so much pressure and he held his nerve.
Murray 6-2 6-7 (7-9) 1-0 Tsitsipas*
Andy Murray is up and running in what you sense is a crucial third set, as Tsitsipas misses with a forehand.
Laura Robson
Former British number one on BBC Radio 5 Live Sports Extra
Andy is still not happy with his shoes, retying them.
He is livid about it.
*Murray 6-2 6-7 (7-9) 0-0 Tsitsipas
A backhand winner gets Murray started, and the Briton moves to 40-15 after Tsitsipas volleys for 15-15.
*Murray 6-2 6-7 (7-9) 0-0 Tsitsipas
After a welcomed nine-minute break and much-needed cool down and change of clothing, the players are back on court.
Andy Murray, who apparently has only brought one pair of shoes with him, gets things under way in the third set.
#bbctennis
Alex Haworth: Classic Murray, in so many ways.
Andrew Morris: Ah. Tsitsipas will roll through the next two sets now; that was Murray's opportunity and he won't get another sniff now.
Garcia 6-7 (6-8) 6-4 6-2 Dart
Britain's Harriet Dart played an excellent opening set to take the lead against France's Caroline Garcia, but has just lost the decider.
The 25-year-old left the court for a lengthy medical time-out in the second set and could not rediscover her first-set form as the Frenchwoman sealed her place in the second round.
Murray 6-2 6-7 (7-9) 0-0 Tsitsipas
Both players leave the court to change their sweat-soaked clothes and presumably shoes too.
Andy Murray was complaining to his team towards the end of the second set that he was slipping in his trainers.
It's hot out there - around 29C and rather humid at Flushing Meadows.
Murray 6-2 6-7 (7-9) Tsitsipas
Ah. A double fault at the worst time for Andy Murray.
Tsitsipas takes full advantage, wrapping up the second set on serve.
A rollercoaster of a tie-break ends 9-7 to the third seed and we're all square on Arthur Ashe Stadium.
David Law
Commentator on BBC Radio 5 Live Sports Extra
We thought these days were gone. Watching Andy Murray, hanging on every nerve.
You can't beat it.
*Murray 6-2 6-6 (7-7) Tsitsipas
And now it's Tsitsipas with a set point of his own...
But Murray holds his nerve and a miss from the Greek puts him back in the driving seat.
Murray 6-2 6-6 (6-6) Tsitsipas*
Murray, soaked in sweat, can't take the first of his set points and nets.
And that's brilliant from Tsitsipas, who sends Murray scrambling across the back of the court to level things at 6-6. Great entertainment.