Some clean hitting so far from Carlos Alcaraz, off both wings, and that wrist continues to hold up well.

He works himself an opening at 15-30 but Tommy Paul is not backing down.

A strong forehand of his own, followed by a big serve down the middle take him to game point and an ace down the T seals the hold.

A double fault and forehand into the net give Tommy Paul a sniff of a chance but that's it.

Solid hold for Carlos Alcaraz, secured as Paul drags a forehand wide.

Image source, Getty Images

On Louis Armstrong Stadium, Wimbledon champion Linda Noskova is moving closer to the women's quarter-finals.

After breaking Marta Kostyuk's serve, she holds straight afterwards for a 5-3 lead.

Warm-ups done. We're just about ready to go on Arthur Ashe Stadium.

Carlos Alcaraz faces his biggest test yet since returning from injury. He'll serve first.

Jeff Tarango
Former American tennis player on BBC Radio 5 Live

Paul needs to keep Alcaraz stretched out as much as possible. I wouldn't get into a backhand to backhand rally. I would say isolate him as much as possible. It hurts his chances of using that great drop shot.

Image source, Getty Images

You have to go back to 2003 for the last time an American man won the US Open - or any Grand Slam, for that matter.

Emulating Andy Roddick is the aim for Tommy Paul then and, with no Jannik Sinner and Carlos Alcaraz returning from a lengthy lay-off, hopes of a home winner this year at Flushing Meadows have grown.

There are five Americans in the fourth round and if Paul can put out Alcaraz - and reach the quarter-finals at his home Slam for the first time - then US hope may turn to belief.

Paul has beaten Alcaraz twice before so he will cling to that.

However, the Spaniard has won six of their eight meetings and Paul has lost all eight of his previous matches against top-five players at majors.

Two very quick holds, something of a rarity in this match, and it remains on serve in the second set.

Still firmly in the balance.

Image source, Getty Images

While Carlos Alcaraz at times appeared frustrated with his own inconsistency in the last round, the former world number one continues to demonstrate progress.

Alcaraz landed 21 winners as he extended his career-best streak of Grand Slam singles match wins to 17, but that was counteracted by 33 unforced errors and a first-serve success rate of just 67%.

He did not have it all his own way against Wu Yibing and repeatedly made his feelings clear on the court.

He surrendered early advantages in the first two sets - his first serve dipped to 53% in the second set - but managed to reset to avoid further complications.

"Every win Alcaraz gets, he is becoming more of a favourite," former Wimbledon champion Pat Cash said on BBC Radio 5 Live.

"Four months off, no matches and win the US Open? He is a class above everybody else, when he is good, and he is getting better by the moment.

"The way he is moving, there is no reason for him not to do well."

It's still on serve in this second set but it's Marta Kostyuk who has started it most impressively.

The Ukrainian 11th seed has secured two pretty straightforward holds and forced a break point on Linda Noskova's serve.

It came up in slightly unusual fashion with Noskova a couple of inches away from a winner as she attempted to hammer a forehand down the line - but the ball cannoned into the top of the net post and ballooned out.

The Czech managed to brush that off, though, and dig out a hold.

Image source, Getty Images

Carlos Alcaraz swept Wu Yibing aside to reach the fourth round - and said he is getting better with every match as he continues his return from a long-term injury lay-off.

The Spaniard underlined why he remains a serious contender to defend his title in New York with a 6-3 6-4 6-1 victory over China's Wu.

The 23-year-old's opening-round match in Flushing Meadows was his first on a singles court for 139 days after injuring his wrist in April.

Alcaraz came through his opener in straight sets but had to battle back from a set down against Portugal's Jaime Faria in the second round.

"To be honest, I'm better than I thought," the seven-time major champion said.

"Physically I thought I was going to be bad after the first match, but I am recovering really well. I am doing great things off the court to be in a good state.

"Right now, I think my level is really good. I think I have caught the rhythm of the competition.

"Every time that I step on the court I give it all. I'm just trying to improve, be better every match and I think I'm getting there."

He takes on Tommy Paul next on Arthur Ashe.

The Wimbledon champion is a set away from another Grand Slam quarter-final then.

But Marta Kostyuk showed enough in that first set to make it clear there is still plenty of life left in this match yet.

Meanwhile, we're getting ever closer to the next match on Arthur Ashe...

Image source, Reuters

Linda Noskova gets it done on the second set point, serving down the T initially, and Marta Kostyuk's second strike goes long.

The Czech sixth seed is a set away from the quarter-finals and a possible meeting with world number one Aryna Sabalenka, who won her fourth-round match earlier today.

If it's possible to drink water from a bottle angrily, Marta Kostyuk does just that at the change of ends - she's clearly frustrated at losing her serve at such a crucial time of the match.

Linda Noskova pings a backhand winner down the line to make the perfect start as she attempts to close out the set, but Kostyuk shows some excellent defence to make it 15-15.

The next two points are shared, before Kostyuk goes long with a forehand return - set point to Noskova...

Double fault! Deuce.

Two superb forehand winners by Linda Noskova earn her a game point and Marta Kostyuk's forehand breaks down.

The Wimbledon champion will serve for the first set after the change of ends.

Marta Kostyuk, having held serve quite comfortably, has 15-30 on Linda Noskova's serve - she's two points away from the first set...

But Linda Noskova recovers well, winning three straight points to level the set once more at 5-5. Game point is taken with a great backhand drop volley at the net.

Image source, Getty Images

Marta Kostyuk has been one of the form players in 2026, winning the WTA 1000 event on the clay in Madrid and following that up with runs to the semi-finals of both the French Open and Wimbledon.

She gets a chance to break back straight away when Linda Noskova smashes an overhead into the net, and then takes it as Noskova nets a volley from Kostyuk's attempted passing shot.

Marta Kostyuk goes well wide with a forehand on break point down and Linda Noskova breaks for a 4-3 lead in the opening set.

Czech player Noskova lost fairly early on in Toronto and Cincinnati after winning Wimbledon, but she's back at the business end of another Grand Slam.

Image source, Reuters

This match is a repeat of the semi-final at Wimbledon a couple of months ago, which Linda Noskova won en route to winning a maiden Grand Slam singles title.

Noskova and Marta Kostyuk swapped breaks at the start of the match and it's been on serve since then, with Ukrainian Kostyuk leading 3-2.

Women's top seed Aryna Sabalenka, on the challenges opponent Taylor Townsend presented in their fourth-round match: "What an incredible player she is approaching the net. A great returner, moving well, very brave.

"You can see how focused she was, and it was really challenging playing her, especially here. Thank you so much [to the crowd] for being so respectful to me. I knew coming into this match that you guys would be on her side, but you were sometimes cheering for me and I really appreciate that.

"I'm happy to be through against this really tough opponent."

On falling a break down in the second set: "I was like OK, you were down the break, just try to return the serve and put as much pressure on her as possible basically.

"I was just trying to stay focused on myself, not only point by point but ball by ball.

"I'm happy I was able to turn around the second set, I think it was a key moment."

Image source, Getty Images

Image source, Reuters

Aryna Sabalenka got through her fourth-round match in an hour and 15 minutes, and it means the crowd on Arthur Ashe Stadium will have to wait about an hour before they see defending men's champion Carlos Alcaraz in action.

Sabalenka will play the winner of the match currently on Louis Armstrong Stadium between Linda Noskova and Marta Kostyuk, which is on serve at 2-1 in the first set.

We'll have updates of that match shortly, along with reaction from Sabalenka and build-up to the Alcaraz match against American Tommy Paul.