Break point for Jan Choinski as Roberto Carballes Baena loops a forehand long but the Briton puts a relatively routine backhand into the net.

Those unforced errors have been the story of the match so far for Choinski as the Spaniard goes on to hold.

Image source, Getty Images

When Dominic Thiem first appeared onto the tennis scene, plenty of people had the Austrian down to win quite a few Grand Slam titles.

A combination of his career running parallel with some of the greatest to play the game and a series of injuries mean his tally is just one - the 2020 US Open.

Those injuries have taken their toll over the years and, aged 30, he is preparing for the final Grand Slam appearance of his career before he retires later this year.

Thiem's first-round opponent is American Ben Shelton, the number 13 seed, who reached the semi-finals in New York last year.

Image source, Reuters

Amanda Anisimova finally gets the job done!

She led Zheng Qinwen 5-1, then lost her serve twice, but breaks the number seven seed for the third time in the match to take the first set.

The American is one set away from claiming the scalp of the Olympic champion.

Jonathan Jurejko
BBC Sport

It's been tough going for Jan Choinski.

Roberto Carballes Baena is the sort of player who gives you nothing: sprinting, scrambling, sticking the ball back.

The solid Spaniard is asking questions of the big Brit by constantly getting the ball into his half of the court.

Choinski, so far, is not answering them.

Choinski is pushing his opponent back in the court during the rallies but gets tense as the point wears on and, when he tries to go for the lines, continues to make unforced errors.

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

Alexander Zverev for me, I think it's his year.

I would make him the favourite for the men's draw. You can't really say that with Novak Djokovic. Novak hasn't played since he won the Olympics, I just wonder what his 'why' is now for playing tennis.

Does Djokovic want number 25 as much as he wanted the Olympics? Does he want this specific one as much as Zverev wants his first ever Grand Slam? I just don't know. We know Zverev has won more matches than anybody else this year.

There is a bit of an opening for somebody outside of the top three of Djokovic, Carlos Alcaraz and Jannik Sinner and I feel like if anyone can do it, Zverev is the man.

Maria Sakkari needed some treatment on a shoulder or neck problem midway through her first set against Wang Yafan and that injury has got the better of the number nine seed from Greece.

After losing the first set 6-2 to Wang Yafan of China, Sakkari chose to pull out of the match and she exits at the first-round stage for the second year in a row.

Well, well, well...

Amanda Anisimova has twice missed the opportunity to serve out the first set and Zheng Qinwen, with a couple of breaks back, is back on serve at 4-5 down.

Jonathan Jurejko
BBC Sport

So how did Jan Choinski end up representing Great Britain?

In 2019, Choinski called British Davis Cup captain Leon Smith - out of the blue - to speak about the process of changing allegiance.

While Choinski knew there would be no funding for a player of his age and ranking, he still made the switch with the carrot of potential wildcards during the British grass swing if he performed.

That was the case in 2023 when he was given a Wimbledon wildcard. Earning £55,000 by beating Dusan Lajovic in the first round would have proved very handy indeed.

Choinski has showed the willingness to play and travel a lot, so that pay day and the cash earned from another Wimbledon wildcard this year has been put to great use.

Now he has another £75,000 in the bank account after reaching the US Open main draw.

Image source, Getty Images

Carballes Baena is scrambling all over the court, making Jan Choinski play, and his work rate pays dividends.

The 31-year-old earns set point and takes it at the first attempt with a backhand winner down the line into the empty court.

A lot for Choinski to ponder during the break.

Roberto Carballes Baena is playing some lovely stuff now as a fine backhand winner down the line sees Jan Choinski turn around and plod back to the baseline with his head down - nothing he could do about that.

An ace seals a hold to love and the Spaniard is one game away from winning the first set.

Just over half an hour played on Grandstand and men's fourth seed Alexander Zverev serves out the first set against fellow German Maximilian Marterer.

Image source, Getty Images

Zheng Qinwen has work to do here, she has been second best against Amanda Anisimova, who in truth could have won all of the opening six games of their first-round match on Louis Armstrong Stadium.

Anisimova is serving for the first set, and seventh seed Zheng is one of a number of top players struggling early on in New York.

Greece's Maria Sakkari, the number nine seed, trails Wang Yafan 5-2 with a double break in the first set, while Elina Svitolina is down 4-2 to Maria Lourdes Carle.

Few would have expected to see Jan Choinski's name in the US Open first round.

But he has played his way into the main draw by beating Argentina's Pedro Cachin, France's Valentin Vacherot and American Maxime Cressy.

"I wouldn't say I had low expectations but I came with not having played on hard court for quite some time. But as I went through quallies my level was stepping up," he told Sky Sports.

"I need to stay calm in my service games. I don't have any expectations, I just want to leave it all out there.

"I know I have to play a good level to have a chance. I will be fighting to the last point."

A spot of bother for Jan Choinski at 0-30 but he pulls out two big first serves when he needs them to get level.

The Briton undoes his good work with an unforced error on his forehand offering a break point, before Roberto Carballes Baena goes long with a backhand to take the game to deuce.

The Spaniard secures the break at the sixth time of asking following a lengthy back-and-forth deuce as Choinski skews a forehand wide.

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

On the men's side [of the draw], obviously the eye turns to the three main names, Carlos Alcaraz, Novak Djokovic and Jannik Sinner.

The women's draw always feels like a land of opportunity because there are so many big names and so many players that have won Grand Slam titles within it but I think both draws this time could be different.

The Olympics makes it so different from every other year.

A first Grand Slam title has so far evaded Germany's Alexander Zverev. He was beaten in a classic US Open final by Dominic Thiem in 2020 and he also reached the final of the French Open earlier this year, losing to Carlos Alcaraz.

Could this be his year in New York?

He's made a fine start against compatriot Maximilian Marterer, breaking in the opening game of the match and leading 3-2 in the first set.

BBC Radio 5 Live

Did you miss BBC Radio 5 Live's preview of the 2024 US Open last week?

Fear not - it's still available to listen to at your leisure on BBC Sounds.

Jonathan Jurejko
BBC Sport

You can be forgiven if you don't know too much about Jan Choinski.

Choinski, 28, has qualified for a Grand Slam main draw for the first time, having come through those three matches at Flushing Meadows last week.

After switching allegiance to Great Britain in 2018, the German-born giant is the nation's men's number 10 and is ranked 276th in the world.

Choinski reached a career-high ranking of 123rd last year, but has struggled for consistency this season.

Most of his playing time has been on the ATP Challenger Tour - the level below the main tour - and this is only his fourth top-tier match of the year.

China's Zheng Qinwen has had a 2024 to remember, reaching the Australian Open final and then winning Olympic singles gold in Paris.

She made a slow start against Amanda Anisimova, the world number 50 from the United States, but has fought back from 0-40 down on her own serve to hold and level at one game all in the opening set.

Image source, Getty Images

Much of our early focus right now will be on Briton Jan Choinski's match against Spain's Roberto Carballes Baena but here's a snapshot of what else to look out for today.

• American defending champion Coco Gauff faces France's Varvara Gracheva second on Arthur Ashe Stadium.
• Britain's Harriet Dart plays France's Chloe Paquet last today on Court 16.
• Closing the action on the showpiece court at Flushing Meadows during the evening session is Serb defending champion Novak Djokovic, who faces Moldova's Radu Albot.