Dean stars with four wickets; Wong takes three wickets on debut
Dunkley hits her first ODI century - off 87 balls
Lamb and Beaumont put on 127 for first wicket
England now lead multi-format series 6-2
Highlights on BBC iPlayer from 07:00 BST on Saturday
Lauren Winfield-Hill
England batter on BBC Test Match Special
They've set their stall really well. A great partnership and a really healthy strike rate here for England.
South Africa haven't been able to set into any plan. The plan that they are bowling to is not obvious.
Melissa Story
BBC Test Match Special
England batters looking comfortable out there.
Four dots from Kapp to complete the over. But what can South Africa do here? We're only seven overs in and England already look completely in control.
Melissa Story
BBC Test Match Special
Tammy Beaumont is looking in fine touch here for England.
It's just a change of end for Marizanne Kapp but it's the exact same result as Beaumont pulls two short balls for two more boundaries.
This is very unlike Kapp, she's allowed England to get off to a flyer.
Georgia Elwiss
England all-rounder on BBC Test Match Special
It looks a little bit green but it is a bit of a slow wicket today at Bristol. It looks a pretty good wicket. England will be looking to post a big total.
Melissa Story
BBC Test Match Special
It feels like it's very much a batting wicket today.
This is frustrating for South Africa. From one end, Ismail is bowling nice and tight but the other is leaking runs.
Khaka offers Emma Lamb some width and she smashes it past point for four more.
An early bowling change for South Africa as Ayabonga Khaka replaces Marizanne Kapp, who struggled for consistency to Tammy Beaumont in particular.
Georgia Elwiss
England all-rounder on BBC Test Match Special
England are being made to work harder today than they were in the first game. South Africa have straightened up the bowling to Emma Lamb in particular.
A maiden from Ismail, who has started brilliantly.
South Africa bowled far too short to Emma Lamb on Monday but she's been tested with much more consistency so far.
Beaumont 17, Lamb 6
Short and wide again and cut away for four again.
Kapp is struggling to back up Ismail here and Beaumont is gratefully putting the bad ball to the boundary.
The square boundaries are pretty long but the ball is racing along.
Kapp drops short again and Beaumont flicks it off her hips for four more.
She won't miss out on that.
A no-ball from Shabnim Ismail brings a free hit, but Tammy Beaumont horribly mistimes it and it plops painfully in the air up to mid-on.
Rather underwhelming.
Before the start of play, Tammy Beaumont was giving some last-minute advice to England's bowling debutants.
Image source, Getty ImagesA loose first over from Marizanne Kapp and Tammy Beaumont takes two boundaries from it, the first viciously cut away and the second driven down the ground.
It looks a lovely batting pitch - those two raced to the ropes.
#bbccricket
JafarAstro: Excited to see how Wong and Bell fare today! I love watching Crossy and Brunt bowl but it’s exciting to see the new blood will fare!
Ooooh! That's what South Africa have been missing.
Ismail's extra pace nips in and slices Emma Lamb in half and races past the keeper for four byes.
Bang on target first ball from Ismail and Tammy Beaumont is solid in defence. Two slips in for South Africa - nice and aggressive.
Tammy Beaumont and Emma Lamb, off the back of her maiden international century at Northampton, make their way to the middle.
It's very hot but cloudy, so at least they're safe from the t-shirt tans today.
Shabnim Ismail has the new ball and this is something I'm looking forward to. South Africa have really missed her.