Emma Navarro holds for the first time in this second set.

Much better from the American.

Can she put some pressure on Mirra Andreeva's serve?

Well, how about that for a response?

Emma Navarro reduces Mirra Andreeva's lead to a break in this second set.

It feels like she needs the frustration of losing her serve to come out and play with more aggression - and it worked there.

Can she keep it up?

Mirra Andreeva is running away with this.

She gets the double break and it's all of Emma Navarro's making.

The American 11th seed saves two break points before succumbing to the third.

The Russian teenager is in cruise control now.

Image source, EPA

Martina Navratilova
Nine-time Wimbledon singles champion on BBC TV

Image source, Getty Images

Navarro is standing about 4ft behind the baseline. She would make her life so much easier if she just moved forward a little bit so she is not having to cut the corner to reach a shot.

Navarro is hanging in there but she is not getting any freebies from Andreeva. She is also struggling to get first serves in.

Still on serve in the fourth set on Court One.

The power of the Ben Shelton serve is such that Lorenzo Sonego has to be faultless in his returning.

He's been extremely good today but Shelton still holds to love in his latest service game.

We're approaching the business end of the fourth now. Will we get a fifth?

Well, that is an almighty hold for Mirra Andreeva.

Her level has definitely dropped here but the Russian manages to save three break point opportunities from Emma Navarro.

The American is hitting so much better and playing far more aggressively.

But that was a huge missed opportunity for her.

Laura Robson
Former British number one on BBC Radio 5 Live and BBC Sounds

Image source, Getty Images

Andreeva just has more options today - she can add the height when she needs to or the injection of pace, especially on the first serve that we have seen time and time again.

It just looks like she has so much more confidence. In these tight matches, she can sometimes get quite tight and irritable but we haven't seen her get close to that today.

Gary Rose
BBC Sport at Wimbledon

Emma Navarro looked up to the sky after being lulled into moving into the middle of the court before Mirra Andreeva sent a forehand down the line.

The celebration of getting a break was all too brief for Navarro, as Andreeva just swiftly broke again.

Image source, Reuters

Lorenzo Sonego holds to love as if to let Ben Shelton know that he's not going anywhere in this match.

The Italian hammers home the point by bring up break point with a vicious overhead smash but Shelton shows fantastic touch at the net to save it.

Serve and volley, the ball dips at his feet but the half-volley drop shot from Shelton in near-perfect.

It's getting noisy out there with shouts from both players but after another massive serve down the middle, it's a big hold for the American.

Image source, PA Media

Three games have been played in this second set and there have been three breaks of serve.

Mirra Andreeva gets her nose back in front again.

She came out punching there, probably angered by that sloppy service game last time out.

Emma Navarro's playing with so much more aggression now and it's paying off.

The American breaks back to put us back on serve in this second set.

A big serve down the T clinches a comfortable hold for Ben Shelton.

The American 10th seed is showing no signs of letting up after his impressive showing in the third-set tie-break.

Gary Rose
BBC Sport at Wimbledon

There's more people in their seats now, perhaps drawn in by the oohs and ahhs that followed that amazing first-game rally that ended with Mirra Andreeva getting an immediate break. Emma Navarro must be wondering what she has to do to beat the teenager.

Oh my goodness.

Mirra Andreeva, that is phenomenal.

The Russian was 30-0 down but wins three points in a row to earn the break point.

The longest rally of the match follows, with Andreeva spending most of it defending against the aggression of Emma Navarro.

But the teenager turns defence into attack to hit a cross-court forehand winner for the break.

A very telling stat has just flashed up on BBC coverage.

Lorenzo Sonego has a 6-32 record against top 10 players. He has lost his past 14 such encounters.

The Italian needs to win the next two sets to halt that sequence - he takes Ben Shelton to deuce to start set four but is fuming after a backhand goes long and the American goes on to hold.

Jonathan Jurejko
BBC Sport senior tennis reporter at Wimbledon

Image source, Getty Images

One is a chatty 18-year-old long tipped as a future Grand Slam champion.

The other is a straight-talking 53-year-old former Wimbledon winner, who has also coached another top player to the title.

Together, Mirra Andreeva and her coach Conchita Martinez are forming a successful double act.

"Mirra is a very special player and very complete in everything she does – but also improvable. I think she has a lot to learn," said Spaniard Martinez, who memorably won the 1994 title.

"If I won Wimbledon - I was more of a clay-court player - then I think she has a good shot of winning."

Read more about the blossoming partnership which Andreeva and Martinez hope will lead to the Wimbledon title.

Image source, Reuters

Is there an obvious weakness to Mirra Andreeva's game?

The Russian had the most difficult service game of the set there and Emma Navarro earned a break point.

But the teenager fires off a 119mph serve that Navarro can't return to take it back to deuce, before holding to take the first set.

She showed a bit of everything in that set, dictating from the baseline and overpowering Emma Navarro - who was broken twice.

You can see why many are tipping her as a future Grand Slam winner.

Marion Bartoli
Former Wimbledon champion on BBC Radio 5 Live and BBC Sounds

I would like Emma to change up a bit from the back of the court rallies, bring Mirra a bit more forward and giving her different angles. Even though you might lose the point, it's still change up. You don't want to stay in the same tune all the time.

Martina Navratilova
Nine-time Wimbledon singles champion on BBC Two

Andreeva does so well and takes the ball on so quickly. She is fast around the court and reads the play really well.

You can have all the talent in the world but you need to have the determination too. She is the whole package and is still just getting started. Conchita Martinez has backed a good horse.

Ben Shelton was virtually flawless in that tie-break, anticipating everything that Lorenzo Sonego threw at him.

He shares a satisfied look with his friends and family at courtside after a stunning backhand return lands on the baseline to seal an emphatic breaker in which Sonego won just one point.

The 10th seed a set away from a first Wimbledon quarter-final.