US Open day six - listen to BBC Radio 5 Live commentary (UK only)
Coming up: Carlos Alcaraz faces China's Wu Yibing in third round
Defending men's champion Alcaraz is working his way into tournament after a lengthy spell out with a wrist injury
Two-time defending champion Aryna Sabalenka beats Kamilla Rakhimova 6-3 6-4 to reach fourth round
Third seed and home hope Jessica Pegula survives a scare to beat 2021 runner-up Leylah Fernandez 1-6 6-4 6-3
Marta Kostyuk through in straight sets, 2021 champion Daniil Medvedev in action
Jessica Pegula admits she was a bit "lazy" in the first set.
But the American hope goes on to face 16th seed Sorana Cirstea, who ended Italian 19th seed Jasmine Paolini's tournament.
Full quotes coming right up.
Next up on Arthur Ashe Stadium, Carlos Alcaraz continues the defence of his title.
Pegula 1-6 6-4 6-3 Fernandez
Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra
Good performance.
Jessica Pegula was in all sorts of trouble in that first set.
The US Open, her home tournament, Jessica in other tournaments, goes 'Not my day today', but being the US Open and where she has been successful, she is a great fighter.
Pegula 1-6 6-4 6-3 Fernandez
There's a look of pure relief on the face of Jessica Pegula.
A final volley lands in the court and, from looking down and out after a really tough start, the third seed escapes to keep alive her hopes of landing a first major title this fortnight.
*Medvedev 6-4 3-3 Rinderknech
A little fist pump from Rinderknech as he makes his way to his seat for the changeover.
We're still on serve but his tennis has been better in this set - fewer errors - and he knows it. He's got good support here too.
*Pegula 1-6 6-4 5-3 Fernandez
Jessica Pegula swats a forehand down the line for 15-0, draws an error from Leylah Fernandez, and then throws in an ace.
Three match points!
*Pegula 1-6 6-4 5-3 Fernandez
Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra
New balls coming out as well. They will zip through a little bit and there's a chance of unforced errors. Leylah Fernandez is going to change her racquet, which I think is a good thing.
*Pegula 1-6 6-4 5-3 Fernandez
Into the net from Jessica Pegula, and Leylah Fernandez will have one final shot at breaking the world number three to keep her hopes alive in this match.
Pegula 1-6 6-4 5-2 Fernandez*
What a time to pull that service game out of the hat.
Jessica Pegula gets up and running with an ace, and cruises to a rare love hold to move just one game away from victory.
It's been a battle, but the third seed is almost there.
*Pegula 1-6 6-4 4-2 Fernandez
Image source, Getty ImagesLeylah Fernandez isn't out of this yet.
The 31st seed holds from deuce to stay in touch at 4-2 as we hit the two-hour mark on Arthur Ashe Stadium.
Pegula 1-6 6-4 4-1 Fernandez*
A superb backhand winner from Jessica Pegula, who has found a much more consistent level to wrest control of this, gives her 0-30 on Leylah Fernandez's serve.
Fernandez fires back with back-to-back winners off either wing, but misses a forehand for deuce.
*Medvedev 6-4 1-2 Rinderknech
We remain on serve early in this second set but there was some encouraging tennis in there for Rinderknech, particularly during the third game when he came out on top of a rally at the net with a clever volley.
Pegula 1-6 6-4 4-1 Fernandez*
Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra
Leylah Fernandez has got to bring the margins in and go down the middle a little bit. If you're a bit short, Jessica Pegula is damaging.
Pegula 1-6 6-4 4-1 Fernandez*
Image source, Getty ImagesNow the crowd really believe Jessica Pegula is going to pull this off.
The 2024 finalist drives a forehand into the back of the court and Leylah Fernandez can't get enough behind her racquet to send it back in play.
The third seed is two games away from the fourth round, almost an hour and a half after she lost six of the first seven games.
*Pegula 1-6 6-4 3-1 Fernandez
Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra
Another solid game. Jessica Pegula continued on from the second set, which is crucial.
No lapses in concentration, which is so often easy to do. Pegula has done well.
*Pegula 1-6 6-4 3-1 Fernandez
Abigail Johnson
Commentator on BBC Radio 5 Sports Extra
That is what the best do, they turn up when it counts.
*Pegula 1-6 6-4 3-1 Fernandez
Image source, Getty ImagesThere it is!
The world number three edges closer to a great escape on Arthur Ashe after Leylah Fernandez sends a backhand out.
After looking in control for the first half of the match, the Canadian is beginning to struggle now.
Pegula 1-6 6-4 2-1 Fernandez*
Leylah Fernandez takes a moment at the back of the court after netting to give Jessica Pegula 15-30.
The young Canadian's shoulders slump as another forehand finds the net.
Two break points. Unlike Fernandez, Pegula hasn't missed one yet...
Medvedev 6-4 Rinderknech*
That first break going Rinderknech's way seemed to rally Medvedev and he turns it on in the ninth game, sending a fine forehand winner down the line on his way to a second break and the chance to serve for the first set, which he does with little trouble.
Pegula 1-6 6-4 2-1 Fernandez*
Pat Cash
Former Wimbledon champion on BBC Radio 5 Sports Extra
Leylah Fernandez screams. A scream of frustration...
Pegula 1-6 6-4 2-1 Fernandez*
Image source, EPALeylah Fernandez yells at herself as she misses yet another break point.
She has made just three from 11 on those opportunities. It is clearly really beginning to bother her.
The Canadian lets out another shout after hauling Jessica Pegula back from game point with a forehand winner - but Pegula eventually escapes with a service winner.
