Here's a look at the first six of the game.

Lizelle Lee waits for the right ball to powerfully square-cut Ecclestone for four.

The Proteas need 126 from 35 overs - at a rate of 3.6 runs per over.

It's still Gunn from the New Road End - Lee and Van Niekerk are moving along nicely, picking off the singles without any drama.

Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special

Van Niekerk got into the slog sweep position and hit through the line. With mid-on up, she had margin for error, even if Jenny Gunn has a long reach. This is a nice little partnership.

Van Niekerk finds the gap, getting down on one knee to launch Ecclestone over mid-on for four as the teenager, bowling in sunglasses, holds her head in her hands. Van Niekerk has now overtaken opener Lee as a single brings up the fifty stand - Lee matches her with a single to the cover sweeper so they both now have 25.

Natalie Germanos
BBC Test Match Special commentator

Van Niekerk is the type of captain to lead from the front, she's been captain nearly two years now.

Lee sweeps Gunn for two to bring up 50 for South Africa, they're going along rather nicely after losing those two early wickets.

Time for some spin - and time for Sophie Ecclestone to show why she's been preferred to fellow left-arm spinner and World Cup winner Alex Hartley for these first couple of ODIs. A tidy first over yields three singles, including Van Niekerk's first non-boundary scoring shot.

Mike Flint: When Sarah Taylor finally hangs up the gloves we'll need two to replace her.

This is worth watching again and again.

World class wicketkeeping from Sarah Taylor.

SA 43-2published at 10 overs

10 overs

Lee 19, Van Niekerk 18

Shrubsole's off and England turn to Jenny Gunn's medium pace - and having seen the Taylor stumping, Van Niekerk doesn't dare move when a legside wide is signalled. But a loose delivery is hoisted over mid-wicket for the first six of the day. DVN really had to fetch that from outside off stump.

Van Niekerk then swats back-to-back fours wide of mid-off - she has 18 from 24 balls, exclusively in boundaries.

Another one for the Brunt family album - here's the half-centurion's opening wicket.

Lee has been the more aggressive of this batting pair, but a maiden over from Brunt - great line and length - keeps her quiet.

Now then, England - how long before a bowling change?

Having previously declared that "Sarah Taylor could stump a statue down the leg side", cricket writer Vithushan Ehantharajah has found the proof!

Image source, Twitter

TV viewers who have never been to Worcester are being taunted by a close-up of one of the famous New Road cakes - while Anya Shrubsole looks a little annoyed at the amount of time Lizelle Lee is taking to get ready. (By the way, full marks to South Africa for their over-rate - through 50 overs in not much more than three overs). And having taken her time to settle, Lee powerfully square-cuts Shrubsole for back-to-back fours.

Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special

One difference between the two teams is the wicketkeepers. Sarah Taylor being able to stand up to the stumps is a massive advantage for England, it keeps batters in their creases and under pressure.

Lee adds a single, Van Niekerk can't pierce the infield as a diving stop by Nat Sciver at mid-wicket leaves them not daring to attempt a run.

Lydia Greenway
Ex-England batter on BBC Test Match Special

If there was a bit more pace in the pitch, I'd be more inclined to think about a short leg. Because it's slower, they have a slip instead.

Van Niekerk still finds it tough against Shrubsole, who has only conceded two runs off the bat from her first two-and-a-half overs. However, Van Nierkerk executes a textbook cover drive for four, holding the pose.