Carol Young Suh Lee has decided to head off court for a reset.

Katie Boulter decides to make the most of the American's absence and she hammers home a few practice serves.

Finally! Katie Boulter clenches her first and roars towards her team.

That took a while, but she fends off four break points in a mammoth game and finally wraps it up on her fourth set point as Carol Young Suh Lee finds the fence again.

Katie Boulter flings a forehand wide to hand Carol Young Suh Lee another break point, but the American can't deal with the pace on Boulter's next serve.

And the British number one brings up set point number four with a fierce serve-forehand winner combo.

Carol Young Suh Lee finds the fence, too. Deuce.

Carol Young Suh Lee has somehow managed to hold on, saving three set points, and now she can break as Katie Boulter nets.

A third set point comes and goes for Katie Boulter as Carol Young Suh Lee makes another move to the net and aggressively thumps down a winner.

Heather Watson
British tennis player on BBC Radio 5 Sports Extra

Lee is doing such a great job of putting that pressure on Katie and making her play the extra ball.

Ah. The frustration shows for Katie Boulter as she finds the fence again. Deuce.

A brave move by Carol Young Suh Lee to make her way to the net and she gets her reward, slamming down a winner.

But Boulter finds her forehand again and the American can only fling her racquet at the ball.

Katie Boulter saves the break point and then comes up with a massive serve to help save another one.

Now the British number one has the chance to see out the set.

The forehand had been working wonders for Katie Boulter, but she misses another one in this game and Carol Young Suh Lee has the chance to break back.

Heather Watson
British tennis player on BBC Radio 5 Sports Extra

Those two forehands Boulter has just missed is uncharacteristic of her. I think that's a bit of nerves and also just the pressure that Lee continues to put on her.

Katie Boulter has looked fairly comfortable on serve, but now, when the pressure is on her to serve out the first set, she finds herself 0-30 down.

Now it's Carol Young Suh Lee's turn to land a double fault at 40-0 up.

That's the only blip, though, and she'll make Katie Boulter serve for the opener.

A bit of a wobble from Katie Boulter there, but she recovers well and lets out a huge roar of "come on" as she gets the hold and moves one game away from taking the first set.

Image source, Getty Images

Katie Boulter whizzes to a 40-0 lead on serve before a double fault stops her momentum. And there's another! Deuce.

Carol Young Suh Lee holds her nerve to win the next three points and get another game on the board.

Katie Boulter missed the chance to go a double break up earlier in the set, but she can have another go here as Carol Young Suh Lee nets.

Heather Watson
British tennis player on BBC Radio 5 Sports Extra

Katie's got a lot of positive energy bouncing around. There was a big 'come on' after that point. I love her positive body language, I really admire it and I try to use it myself sometimes.

Carol Young Suh Lee hasn't had it easy in her service games.

A flick of the wrist and Katie Boulter lands another stunning forehand winner to bring us to deuce.