England 219-5: Lamb 102, Sciver 55; De Klerk 2-44
Lamb hits maiden international ton off 91 balls; Sciver hits 55 after taking 4-59
SA 218 all out - Tryon hits 88
Multi-format currently level at 2-2 after drawn Test
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Such is England's mentality at the moment they have got a slip in and only two fielders outside the 30-yard ring at the moment.
South Africa captain Sune Luus is struggling - having scored seven from 26 balls - and England are keen to keep the pressure on her and squeeze as much as possible.
Daniel Norcross
BBC Test Match Special
I'm not sure what kind of school that would be.
Alex Hartley
Former England bowler on BBC Test Match Special
Every day is a school day, especially when you're with me!
Here are the two wickets that England, and Katherine Brunt, have picked up so far...
Another tidy over from Sophie Ecclestone.
She seems to be whistling through them at the moment, and she concedes just three.
Time for a drink in Northampton. They'll be needed today. It's warm.
Alex Hartley
Former England bowler on BBC Test Match Special
I've been stood out on the balcony and I hate to say it, it's a little bit too warm.
Emily Windsor
Southern Vipers batter on BBC Test Match Special
You can tell how hot it is because our commentary team usually get themselves outside if they can but they're all huddled at the back of the box for the air con.
A slightly risky single for Wolvaardt to start the Cross over as she pushes the ball to point. There was a moment of hesitation but they get safely home in the end.
Another economical over for England, though, only two from it as they continue to put the squeeze on.
Henry Moeran
BBC Test Match Special
South Africa are not really going anywhere at the moment.
Luus 4, Wolvaardt 21
This South Africa pair seem content to just tick things over for the time being. Only a pair of singles from Ecclestone's second over.
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Henry Moeran
BBC Test Match Special
There is quite a queue for the ice creams. A much bigger queue than at the taco van. It's a bit hot for tacos.
Tidy stuff from Cross before Luus clips the fifth ball through the on-side for a couple.
A single from the last keeps her on strike.
Alex Hartley
Former England bowler on BBC Test Match Special
The last time Ecclestone played South Africa in an ODI, she got her first ever international five-for. So, she'll be confident. But then, I'm sure she's always confident.
Good start from Ecclestone, keeping Wolvaardt tied down. Just two leg byes from the over.
Time for a bit of spin.
Sophie Ecclestone - the number-one ranked bowler in the world - is one with her left-arm spinners.
Alex Hartley
Former England bowler on BBC Test Match Special
Clever, clever batting from Wolvaardt. She's adjusted from the ball before. As a bowler though, you know you can't bowl outside off stump to her. She's got the best cover drive in world cricket.
Emily Windsor
Southern Vipers batter on BBC Test Match Special
That is a fantastic shot from Laura Wolvaardt.
Oh, lovely!
Laura Wolvaardt picks up another boundary as she exploits a little bit of width from Kate Cross.
She keeps the strike with an uppish drive down to third.
She's the key here for South Africa. She's up to 20.
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