Jan Choinski slams another shot wide with stats showing that's his 21st unforced error of the match on the forehand side.

Two break points for Roberto Carballes Baena and he comes through at the second attempt as Choinski goes long again.

It's a long, long way back now for the Briton.

Image source, Getty Images

Ah. Looks like we jinxed Dominic Thiem.

Thiem was cruising towards another hold in the 10th game of the opening set, then hit a double fault on game point at 40-0.

Things unravelled from there.

The 30-year-old Austrian allowed Ben Shelton to fight back and, although the American could not take his first two set points, broke at the third opportunity.

Feels a long way back for Thiem now on his final appearance at Flushing Meadows.

Image source, Getty Images

We're going the distance on Louis Armstrong Stadium.

Zheng Qinwen fires down an unreturnable serve that Amanda Anisimova can only send back into the net and the Olympic champion takes the second set 6-4.

The Chinese player leaves the court at the end of the set and there will be a slight delay before the decider gets under way.

Anisimova has called for the physio, she is getting some spray and padding applied to an already heavily strapped left foot.

Dominic Thiem is hanging tough with Ben Shelton.

The retiring Austrian is not landing many first serves, nor winning many receiving points (just the two, actually).

But he's been digging out the holds to keep this opening set on serve as it heads into the business end.

Jan Choinski saves break point with a backhand volley at the net, before smashing a forehand winner to claim advantage in deuce.

The Briton then comes to the net again, forcing Roberto Carballes Baena to loop a backhand long.

A more aggressive approach from the Briton early in this third set.

Jonathan Jurejko
BBC Sport

Eyebrows were raised by some when Dominic Thiem didn't receive a Wimbledon wildcard just a few weeks after announcing he would retire later this season.

No chance he wouldn't be invited to play at the US Open.

Fighting back from two sets down to beat Alexander Zverev in the 2020 final ensured Thiem will be forever remembered as a Grand Slam champion.

But, as one of the most explosive and energetic players of his generation prematurely calls it a day, the feeling is that he could have achieved so much more.

Wrist injuries are notoriously difficult for tennis players to overcome and this one has robbed Thiem of what should have been his peak years. The same thing happened with another US Open champion in Juan Martin del Potro.

Yet the affable Thiem shows no bitterness. Instead he says he is "super excited" to see what the future brings.

Naomi Broady
British player on BBC Radio 5 Sports Extra and BBC Sounds

One of the toughest parts of the five sets is the ability to keep belief when you do go two sets to love down.

It's not easy to do when you are already feeling fatigued. Just keep it one point at a time, one game at a time and see if you can stay out there for as long as you can.

Jan Choinski battles to keep the ball in play and Roberto Carballes Baena mutters some words of frustration to himself as he nets a forehand.

A superb backhand winner then opens up a chance to immediately break back for Choinski but he spurns the chance with a wild forehand return that goes wide.

Carballes Baena wins the set by taking advantage of a Choinski slip, before firing down an ace.

Alexander Zverev was broken by Maximilian Marterer in the sixth game of the second set to fall 4-2 behind, but the fourth seed responded with an immediate break back and the two German players are into a tie-break.

Naomi Broady
British player on BBC Radio 5 Sports Extra and BBC Sounds

Image source, Getty Images

Jan Choinski is definitely feeling it, even from the back end of the first set - the fatigue maybe showing from the qualifiers.

Roberto Carballes Baena is one of the best at giving his opponents absolutely nothing.

Former champion Dominic Thiem knows this is one of the final times he will step on court at the US Open.

The 30-year-old Austrian doesn't want today to be the final time.

The former world number three is retiring later this year, having lost his peak years because of a debilitating wrist injury and losing his enthusiasm in trying to rediscover his previous level.

A wildcard was given to him by the US Open for a farewell appearance, but the draw has not been kind.

Ben Shelton, the bomb-serving American who knocks down 150mph aces, was a semi-finalist here last year.

So far, the pair are trading service games in the first match of the 2024 tournament on Arthur Ashe Stadium.

David Law
Commentator on BBC Radio 5 Sports Extra and BBC Sounds

So often the approach up to the net by Roberto Carballes Baena is enough to put enough pressure on your opponent to come up with the forced error.

Coming into the net, just taking that central defensive shot away.

Jan Choinski gets a time violation warning and immediately puts a forehand into the net on the next point to offer up a break point.

Has that distracted the Briton?

Possibly, as next point he loops a forehand long following a deep Carballes Baena return.

The Spaniard will serve for the second set.

Image source, Reuters

Zheng Qinwen is finding her form on serve, hitting four aces in one service game and then backing it up with the first break of the second set against Amanda Anisimova.

We could shortly be going into a decider on Louis Armstrong Stadium.

Jan Choinski is in trouble at 0-30 but he plays two well-constructed points to level with Roberto Carballes Baena.

Carballes Baena earns a break point but Choinski saves it with a volley at the net.

The Briton then holds in deuce, stamping the game with an ace.

Naomi Broady
British player on BBC Radio 5 Sports Extra and BBC Sounds

Roberto Carballes Baena is starting to up his depth, barely missing any returns.

Jan Choinski's serve isn't slow, not as his height.

Image source, Getty Images

The US Open can often throw up surprise winners - and this year's Grand Slam finale could be no exception.

With the Olympics taking place just three weeks ago, players are arriving in New York with fewer minutes on a hard court than before, and with more miles in their legs.

"I don't think anyone is coming [to the US Open] in top gear," Christopher Clarey, former New York Times tennis writer, told BBC Radio 5 Live.

"For somebody who is maybe more of a second-tier favourite, this is their year and their opportunity."

Who are the main contenders for glory in New York? Read BBC Sport's US Open preview.

Naomi Broady
British player on BBC Radio 5 Sports Extra and BBC Sounds

The shoulder has been bothering Maria Sakkari since the Olympics so it might still be that problem.

Really tough to see, she is obviously understandably very upset.

David Law
Commentator on BBC Radio 5 Sports Extra and BBC Sounds

I don't see Alexander Zverev as the favourite, I see him as the player who could end up benefitting because the other players are not quite on it.

He has won more matches than anyone else but he has also lost a lot of matches where you think he would win the title from there and then he hasn't.