Katie Boulter saves the first with a massive serve, but Rebecca Sramkova gets the return away on the next one and works her way through the point before unleashing a cross-court forehand winner.

We go to a deciding set.

Rebecca Sramkova was in control of that first point, but she just misses the baseline.

However, a series of unforced errors from Katie Boulter gifts Sramkova two set points.

Great Britain haven't lost a set this week.

Rebecca Sramkova stays calm and composed to hold.

The pressure is back on Katie Boulter, who has to stay firm on serve now if she's to avoid going to a deciding set.

GB captain Anne Keothavong has lots of words of encouragement for the British number one as she returns to the chair.

Sue Thearle
Tennis commentator on BBC Red Button

The journey back from 4-1 down is complete. That's some effort from Katie Boulter and the momentum is, without doubt, with her.

There will be an element of revenge for Katie Boulter today. She's only faced Slovakia's Rebecca Sramkova once before, but she lost that encounter in Rome earlier this year.

It's high risk, high reward tennis from Katie Boulter as she catches the line on one side of the court before pinching the line on the other side and then pushing a winner down the middle.

It's paying off and she gets the hold to level the set.

Lovely stuff from Katie Boulter, who advances to the net to pull off a serve-volley combo.

She's maybe a bit too eager to pull ahead, though, double faulting before fizzing a forehand wide. 15-30.

Katie Boulter ups her intensity and gets the job done, aggressively returning Rebecca Sramkova's serve and forcing the Slovak to hit wide after slamming down a forceful forehand.

Olga Savchuk
Ukrainian former player on BBC Red Button

You just feel from Katie Boulter that she is refusing to lose this game.

Now then, what can Katie Boulter make of this? The British number one attacks Rebecca Sramkova's serve to bring up three break points.

A vital hold for Katie Boulter, and better serving who sends down an ace before wrapping it up with an unreturnable serve.

Sue Thearle
Tennis commentator on BBC Red Button

The atmosphere inside this arena is electric, it's deafening as well. The captains are trying to make themselves heard.

This second set is slipping away from Katie Boulter, who is deep in conversation with Anne Keothavong as she returns to her chair for the change of the ends after Rebecca Sramkova gets the hold.

Olga Savchuk
Ukrainian former player on BBC Red Button

For the players who love to play aggressively, they don't like the slower-paced balls. Sramkova is clearly understanding that, on her serve as well. She is going for big bombs rarely.

Katie Boulter holds up her hands in apology as her weak return unexpectedly drops over the net, and Rebecca Sramkova fails to get there in time.

The British number one can't take the pace out of the next two serves, planting both into the net.

Boulter takes advantage of the second serve on the next point, controlling the rally before sending down a winner past an exhausted Sramkova. Deuce.

And there's the break. The pressure tells as Katie Boulter double faults.

Katie Boulter can only send a big backhand from Rebecca Sramkova into the net and the Slovak has the chance to restore her lead.

Sue Thearle
Tennis commentator on BBC Red Button

If she could see the stats right now, Boulter would feel that she just needs a few more first serves to add a bit of stability. It's still down at 44% for the match. That, you feel, needs a bit of an uptick.

Katie Boulter tries to find the line with a flinging forehand, but she misses by mere millimetres.

The world number 24 pulls herself level at 30-30, though, with a blistering winner after sending Rebecca Sramkova the wrong way.

Emma Raducanu will have enjoyed that one. The British number two has returned to the GB bench to cheer on her team-mate.