Emily Salley
BBC Sport at Wimbledon

Another tough test for Jannik Sinner, but he patiently finds a way through to reach the third round. I'm sure that will be a relief after his surprise Roland Garros exit a month ago.

Nuno Borges gave it his best go and he gets a warm round of applause as he makes his way off court.

Coco Gauff gets fully behind her backhand and wins a couple of points to apply some pressure.

But Solana Sierra responds by going all out on her first serve and Gauff's return loops long.

It's all square!

John McEnroe
Three-time Wimbledon singles champion on BBC Two

It was a great test for Sinner.

He played a guy playing as good as he can play. Threw a lot at him. Made him come up with the goods in intense moments. He has to be feeling good about that.

That to me is just what the doctor ordered. Highly competitive and he lifted, that is a good sign for Sinner.

He is going to go into Friday feeling a lot better than he was when he was two sets to one down on Monday.

Leading 30-0, Solana Sierra has to apologise to Coco Gauff when her drop shot tickles the net cord and just drops over.

Sierra has three set points.

Coco Gauff fires out a couple of aces en route to a hold to love.

A message from the seventh seed that she's refusing to let this second set go.

Over to Solana Sierra to serve for the set.

Solana Sierra looks like she's picked up a few tricks from Coco Gauff. The Argentine plants her feet in the middle of the baseline and fires away a backhand winner.

Gauff will serve to stay in the set.

Coco Gauff holds her nerve to serve out for the hold.

Coco Gauff drops the first couple of points but refuses to let the game - and likely the set - slip away.

Gauff comes through a tense rally, eventually slamming a winner at the net, to lead 40-30 but Solana Sierra takes the game to deuce.

Wide serve, follow it in, plant the forehand winner down the same line. Lovely stuff from Jannik Sinner.

Jannik Sinner's cross-court forehand is a millimetre out. He offers a small smile.

After losing the opening set, Russian eighth seed Daniil Medvedev has taken control against Daniel Merida by winning the next two.

The two-time Wimbledon semi-finalist secured the third set 7-5 and is now a break up early in the fourth and well on his way to booking a third-round spot.

Nuno Borges can't believe his ears as his fizzing cross-court forehand is called out. Centimetres away from 0-30.

He levels the game at 30-all after getting Jannik Sinner on the run but with an audacious forehand drive volley from outside the service box, the defending champion earns match point.

Solana Sierra stretches her lead in the second set with a routine hold to 15.

The Argentine has put a frustrating end to the opening set firmly on the backburner as she looks to stay in contention for pulling off an upset.

Sierra is looking a lot more positive on serve.

Double fault. Erm. 0-15.

Image source, PA Media

Cheers all round as Nuno Borges plants a volley winner for advantage.

Even louder cheers as he teases Jannik Sinner with a drop shot, then sends the Italian darting for the back of the court, and finally taps home an overhead.

How about it, Jannik? Can you serve it out?

Our reporter Liam Loftus has been seeing how far the queue to watch Joao Fonseca goes.

This isn't the most high-tech bit of graphic design you'll ever see, but you can just about see Court Three in the background, with the queue snaking around the vast majority of the outer courts.

Fans have travelled from London, Brazil and Prague to watch Fonseca.

Their man is a set and a break up against Jesper de Jong.

Annabel Croft
Former British number one on BBC One

Oh wow! Nuno Borges was just left stranded and watching that last backhand.

That was one of the best backhands you will see down the line. The trajectory over the net was brilliant.

Perfect response from Coco Gauff.

A hold to love gets her on the board in this second set but there's still a lot of work to do if she wants to avoid this going to three sets.