Postpublished at 18:47 British Summer Time 5 July 2019
*Hercog 6-3 5-5 Gauff
Martina Navratilova
Nine-time Wimbledon singles champion on BBC TV
The momentum has changed already.
The nerves are taking over. The crowd are going nuts for Gauff.
Coco Gauff, 15, beats Polona Hercog to reach Wimbledon fourth round
Qualifier loses first set, saves match points in second, wins 3-6 7-6 (9-7) 7-5
American to face former world number one Simona Halep in last 16
Andy Murray & Serena Williams mixed doubles match postponed
Djokovic through in four sets but fourth seed Anderson goes out
Pliskova wins but Wozniacki loses
Jamie Murray wins mixed doubles but loses men's match
Becky Grey, Emma Sanders and Harry Poole
*Hercog 6-3 5-5 Gauff
Martina Navratilova
Nine-time Wimbledon singles champion on BBC TV
The momentum has changed already.
The nerves are taking over. The crowd are going nuts for Gauff.
*Hercog 6-3 5-5 Gauff
FYI whoever wins this is guaranteed £176,000 for reaching the fourth round.
Mind you, whoever loses still gets £111,000. Not bad.
*Hercog 6-3 5-5 Gauff
Crucial.
Gauff has started targeting Hercog's backhand and it's working. The Slovenian bats the ball into the net.
But she gets it back onto her forehand and hits a cross-court winner.
Gauff screams at her box after hitting a winning volley at the net. Then shouts "come on!" as Hercog can't make it over the gauze twice to give Gauff the hold.
Hercog 6-3 5-4 Gauff*
Tracy Austin
Two-time Grand Slam champion on BBC TV
Hercog tightened up, the moment just became too big for her.
But an excellent fightback by Coco Gauff, who was able to play each point and keep her positivity.
Hercog 6-3 5-4 Gauff*
Simon Reed
BBC Sport commentator at Wimbledon
Listen to this reaction.
Gauff was hanging by a thread, but she allowed Hercog to make the errors.
#bbctennis or text 81111 (UK only)
Foxtrot Tango Mike: Cori Gauff is going to be some player, mind. 15 years old and has never been outclassed once by the seasoned professionals.
Hercog 6-3 5-4 Gauff*
She's done it!
Hercog's forehand goes into the net and that's the break. Is this going to be the best comeback EVER?
*Hercog 6-3 5-3 Gauff
A brilliant passing shot from Gauff and the 15-year-old has a second break point.
What is happening?!
*Hercog 6-3 5-3 Gauff
Hercog hits Gauff with a kick serve and the American can't chase down the next ball. Back to deuce.
*Hercog 6-3 5-3 Gauff
Hercog hits a forehand long. Suddenly she is looking like the nervous one. Gauff's dad fist pumps as she gets break point.
*Hercog 6-3 5-3 Gauff
Martina Navratilova
Nine-time Wimbledon singles champion on BBC TV
Not just a double-fault, that's a bad double-fault.
That's nerves, that's understandable.
*Hercog 6-3 5-3 Gauff
DOUBLE FAULT. Match point lost.
*Hercog 6-3 5-3 Gauff
Simon Reed
BBC Sport commentator at Wimbledon
Rally of the match. She soaked up all that power - and then gave some right back.
*Hercog 6-3 5-3 Gauff
Ace. Match point.
*Hercog 6-3 5-3 Gauff
A nervy forehand for Hercog is too long. 30-15.
The "come on Cori" fans are in full swing now.
Hercog hits what should have been a forehand winner down the line but Gauff gets there and sets up for a brilliant cross-court forehand out of the Slovenian's reach. 30-30.
*Hercog 6-3 5-3 Gauff
Hercog hits a few tentative shots and Gauff goes on the attack. But the American goes in a bit too hard and the ball lands long. 15-0.
Gauff's backhand return goes wide. 30-0.
Nick Kyrgios, fresh-ish from his defeat by Rafael Nadal, is in mixed doubles action with American Desirae Krawczyk.
The pair have just taken the first set 7-6 (7-4) against Kiwi Marcus Daniell and American Jennifer Brady.
Meanwhile, Jamie Murray, maybe not so fresh from his men's doubles defeat, along with Bethanie Mattek-Sands could be set to go a set behind in his match against British pair Joe Salisbury and Katy Dunne.
They are a break down and 5-4 down.
*Hercog 6-3 5-3 Gauff
Martina Navratilova
Nine-time Wimbledon singles champion on BBC TV
Two athletes going at it. Fantastic stuff.
*Hercog 6-3 5-3 Gauff
Gauff has suddenly come to life. An impressive response to facing match point as the 15-year-old sprints after every ball to hold.
Hercog is serving for the match now though.
#bbctennis or text 81111 (UK only)
Ayo Obit: Pressure for Coco Gauff would come next year when everyone expects a 16 year old girl to at least make the third round of #wimbledon, external