Emma Raducanu can't return a 113mph serve before Zheng Qinwen strikes another winner to pile the pressure back on Raducanu.

Zheng Qinwen lands one right on the line before smashing a winner home for 30-15.

What a rally that is and it's Emma Raducanu who comes away with her fist clenched in celebration.

Some great ball striking on show by both.

0-15.

A clinic in serving from Emma Raducanu and she holds to love.

Solid as a rock.

What pressure?

Emma Raducanu surges into a 40-0 lead.

Emma Raducanu misses the first serve but goes huge with the second and Zheng Qinwen can't hook it back on to court.

15-0.

The shock absorber on the racquet of Zheng Qinwen has flown off and she jogs off to put another one as Emma Raducanu is given another first serve.

Zheng Qinwen is finding her first serve more in this game and it shows as she holds serve while dealing with the pressure from Emma Raducanu.

Big game coming up now for the Briton.

That's more like it from Zheng Qinwen as she hammers groundstrokes Emma Raducanu's way before opening her body and finding the winner with the forehand.

But there is Raducanu with a backhand winner of her own to force deuce again.

Zheng Qinwen will want more serves like that as Emma Raducanu's short return is put away with a clean volley for deuce.

A beautiful slice from Zheng Qinwen up the line forces Emma Raducanu to go into the net with her forehand.

Plenty of tension out here as Raducanu brings up another break point.

Zheng Qinwen is still struggling to find that first serve as she pulls a forehand wide and it gives Emma Raducanu the lead in the game.

15-30.

There's one break back for Zheng Qinwen to take the tension up a notch here.

The Chinese number one has had problems on her serve this set so we'll see what she's got here.

Emma Raducanu drags Zheng Qinwen to the net with a drop shot and then tries to lob her but Zheng puts away the overhead.

Zheng brings up two break points but fails to convert the first.

A bit of pressure for Emma Raducanu now as she double faults her way to 0-30.

Zheng Qinwen attacks the second serve and hits the return deep so Emma Raducanu can only dig it out into the net.

0-15.

Emma Raducanu breaks again!

It's been a stunning start to this second set for Raducanu and she's powering her way to a deciding set.

Zheng Qinwen looks a little lost right now.

Emma Raducanu is controlling things in this second set and brings up two more break points but a fine Zheng Qinwen serve saves the first one.

What about the second one?

Emma Raducanu goes for the forehand passing shot and Zheng Qinwen can't control the volley.

Chance here for the Briton at 15-30.

A perfect sliced drop shot is too good for Zheng Qinwen and she holds to go two games up in the second set.

Great stuff on the Andy Murray Arena!