Denied. Muchova is rewarded for an aggressive approach and makes a volley at the net.

And now an unforced error from Gauff takes us to break point!

But Coco Gauff arrives at a first match point!

A double fault halts Coco Gauff's progress at 30-15.

She couldn't serve out the opening set at the first time of asking, but she doesn't have the comfort of a double break this time around...

Muchova puts away a forehand for 30-30. The tension rises.

Jeff Tarango
Former American tennis player on BBC Radio 5 Sports Extra

Coco Gauff just needed a couple of errors from Karolina Muchova to capitalise.

Gauff has been holding a little easier than Muchova.

Image source, Getty Images

That could be the match!

Coco Gauff strikes at the perfect moment to give herself the chance to serve out the match and book her place in the US Open final.

Huge cheers erupt around Arthur Ashe Stadium. One game to go!

It felt like a chance for Gauff at 15-30, and now it certainly is.

A double-fault from Muchova brings the American to deuce, before Gauff guides a passing forehand beyond her opponent for break point.

Huge point coming up!

And here is what the USTA has said in response to tonight's disruption:

"Following the first game of the second set in the Gauff/Muchova match, play was halted due to a fan-related incident.

"The fan in question affixed himself to the floor and due to the nature of this action, medical professionals, NYPD and security personnel were needed in order to resolve the issue and remove the fan from the stands."

Oh, a horrible miss from Muchova, sending a smash at the net wide of the mark.

That gives Gauff 15-30. This could be the chance she needs.

Coco Gauff moves within two games of the US Open final.

Despite the stakes, the American teenager breezes to a hold of serve. An ace takes her to 4-3 and within touching distance of Saturday's showpiece.

Is this where she makes her move?

We remain on serve in the second set, as Karolina Muchova battles to another hold.

It's a big improvement on her start to the first set, which she had to try and chase from a 3-0 deficit. But can she make inroads on the Gauff serve?

Here's what Stacey Allaster, US Open tournament director, has had to say:

"There were three [protesters]. Two of them were removed, they quietly left without further protest. When security got there, they found that one of the protesters had physically glued themselves in their bare feet to the cement floor," she told ESPN.

"I was senior management as we were assessing the situation. Jake Garner, our referee, was speaking to the athletes along with Donna Kelso, our Grand Slam supervisor.

"Hopefully people don’t get ideas. We know in these large events, environmental protesters use the platform. Security will be resuming along with NYPD to see what we can do to prevent it in the future."

The clock shows the players have been on court for one hour and 20 minutes.

But if you've recently joined us, you'll know that doesn't make an awful lot of sense for a match which started at 00:00 BST.

We had a 50-minute delay due to a disruption in the crowd caused by protestors after Coco Gauff won the opening game in the second set.

We've got a statement from the US Tennis Association chief on that incident now.

A double fault from Gauff offers Muchova hope at 30-30, but the 19-year-old fires back with a forehand and is able to close out the game.

No loss of concentration here. If anything, that enforced break in play has refocused Gauff following that dip late in the opening set.

Well saved. Muchova builds on that winner, securing an important hold to level at 2-2 in the second set. Frustration for Gauff, that was a chance to strike a potentially fatal blow.

What a way to save the break point! A superb lob from Katolina Muchova salvages deuce. That was the only way she was going to be able to beat the American at the net - and she executed it perfectly.

Gauff and Muchova both lost their only Grand Slam final to date against Iga Swiatek at the French Open. Gauff in 2022, and Muchova this year.

Of course, Swiatek isn't around to stop them in New York as they chase maiden Slam triumphs.

But who will get their second shot at glory this fortnight?

Coco Gauff begins her latest push to ensure it is her. A couple of errors from Muchova bring the American to break point...

Both players seem to have returned unfazed by the delay.

Gauff responds with a love hold, sealed with a volley, to show she is ready to pick up exactly where she left off in her bid for a first US Open final.

Image source, Getty Images

Can Karolina Muchova get back on track? It's over to the Czech player to serve as play restarts.

Some accurate hitting helps her take charge at 40-0, but Gauff won't go away, unleashing a backhand winner for 40-30.

That's into the net by the American, though, and Muchova holds following that lengthy delay.

OK, 50 minutes after Coco Gauff held serve in the opening game of the second set, the post-disruption warm-up comes to an end.

We made it people! Let the tennis recommence...

Jonathan Jurejko
BBC Sport at Flushing Meadows

A relieved cheer as Gauff and Muchova walk back out.

People want to see the tennis.

It's been about 45 minutes since the last point.