Singles second round begins on day four of US Open
Britain's Cameron Norrie battles for four hours to beat Francisco Comesana
British number one Jack Draper withdraws from tournament with arm injury
Emma Raducanu drops just three games in dominant victory against qualifier Janice Tjen
Novak Djokovic comes back from a set down to beat qualifier Zachary Svajda
Elena Rybakina, Jakub Mensik and Jessica Pegula all in action
Listen to BBC Radio 5 Sports Extra coverage at top of page (UK only)
*Fonseca 6-7 (4-7) 0-3 Machac
A double-fault from Joao Fonseca brings up two break points for Tomas Machac but after an ace in the next point, Machac misses a volley at the net to earn himself a break.
He soon gets another opportunity though and Fonseca makes a mistake to allow the Czech to take advantage.
A sloppy service game follows but Machac saves two break points to put himself in control of the second set.
Jack Draper's withdrawal means there are just three British players remaining in the singles draws in New York.
Emma Raducanu made it through to round three of the women's draw with a convincing victory earlier today, while Cameron Norrie - who will be in action shortly - and Jacob Fearnley are in the second round of the men's draw.
Lehecka 3-6 6-0 6-2 6-4 Etcheverry
It's all over on court five.
Jiri Lehecka has come from a set down to beat Tomas Martin Etcheverry 3-6 6-0 6-2 6-4.
Cameron Norrie is next up on this court.
Djokovic 6-7 (5-7) 6-3 5-3 Svajda*
A comfortable hold for Novak Djokovic, who seals it with his fifth ace of the match, and is now just one game from the third set.
Britain's Jack Draper has posted on social media, external to confirm his withdrawal from the US Open:
"Hi guys, I'm sorry to say I'll be withdrawing from the US Open. I tried my very best to be here and give myself every chance to play, but the discomfort in my arm has become too much and I have to do what is right and look after myself. Thank you for all the support."
Image source, Getty Images*Djokovic 6-7 (5-7) 6-3 4-3 Svajda
Novak Djokovic has turned this set around now, breaking serve for the second time in a row.
Britain's Jack Draper was the number five seed at this year's US Open, a year on from reaching the semi-finals in New York.
Draper has been struggling with an arm injury in recent weeks and his first-round win over Federico Agustin Gomez was his first singles appearance since losing in the second round of Wimbledon last month.
*Fonseca 6-7 (4-7) 0-1 Machac
A simple hold from Tomas Machac to start the second set.
He's found his rhythm out there.
Fonseca 6-6 (4-7) 0-0 Machac*
Andrea Petkovic
Former world number nine on BBC Radio 5 Sports Extra and BBC Sounds
My hot take of the day is that it's actually helping Tomas Machac that this crowd is largely getting behind young Joao Fonseca.
When looking at the stats, Fonseca made 14 unforced errors compared to 12 unforced errors for Machac - this was a very tight first set.
Machac takes it with his beautiful backhand in those last two points. He went after it relentlessly.
A post on X from the US Open account, external says Jack Draper has "withdrawn from the men's singles event with an injury" and his second-round opponent Zizou Bergs will go through to round three by walkover.
Image source, Getty ImagesFonseca 6-7 (4-7) 0-0 Machac*
Image source, Getty ImagesA second backhand winner from Joao Fonseca puts us back on serve.
However, his backhand volley on the next point is wide and Tomas Machac is able to break straight back.
The Czech closes out a breathless first set on serve and it's advantage to the 20th seed.
*Djokovic 6-7 (5-7) 6-3 2-3 Svajda
But that tactic didn't work for long.
Zachary Svajda slaps a couple of groundstrokes into the net and gives the break of serve straight back to Novak Djokovic.
Djokovic 6-7 (5-7) 6-3 1-3 Svajda*
Goodness me - a double fault on break point down and Novak Djokovic is broken for the first time in the match.
Zachary Svajda is clearly struggling with a bit of cramp or something, meaning he's trying to keep the points much shorter. That tactic is working for him at the moment.
Fonseca 6-6 (2-4) Machac*
Incredible tennis.
Tomas Machac somehow manages to keep himself in the first point before Joao Fonseca is able to get the better of him.
Machac wins successive points on his own serve before forcing an error from the Brazilian to secure the first mini-break.
The 19-year-old responds though with an excellent backhand but loses the first point back against the serve.
*Djokovic 6-7 (5-7) 6-3 1-2 Svajda
If Zachary Svajda has an injury, it doesn't affect him in his latest service game - a hold to love for the 22-year-old American.
He's receiving a massage to his left thigh at the changeover.
*Fonseca 6-6 Machac
Tomas Machac begins his service game with a nervy forehand straight into the net but that is the only point he loses.
Forcing a tie-break with a volley as he is falling to the floor.
Djokovic 6-7 (5-7) 6-3 1-1 Svajda*
Zachary Svajda is definitely not moving as freely and keeps grabbing at his left leg before trying to return serve.
He's also trying to keep points short.
Interesting to see what will happen at the next changeover when the trainer arrives.
*Djokovic 6-7 (5-7) 6-3 0-1 Svajda
Zachary Svajda holds serve quite comfortably but the trainer has been called for - not sure exactly what for, but the American seemingly has a slight physical issue.
Image source, Getty ImagesFonseca 6-5 Machac*
Andrea Petkovic
Former world number nine on BBC Radio 5 Sports Extra and BBC Sounds
This has already been a great match. It is really fun to watch these two fight it out. They are both very talented players.
We know about the ups and downs of Tomas Machac, but I'm sure he would like to keep the ups and eliminate the downs today.
Fonseca 6-5 Machac*
Well, well, well.
Just as I mention that we were yet to see a break point in this match, Joao Fonseca finds himself with a set point at 30-40 against the serve.
However, Tomas Machac clutches up with back-to-back aces before holding.
Fonseca responds with an ace of his own to hold to love and leave Machac serving to stay in the first set.
