Van Niekerk is still bowling round the wicket - much to the frustration of the TMS commentators, as well as me - three runs from the over.

South Africa will not win this game by containment. They have to try for wickets.

Luus whistles through a second over - not quite so many full tosses this time, but Beaumont helps herself to another four as England take seven from it. This stand is worth 64.

50 for Tammy Beaumontpublished at 26 overs

26 overs

Eng 107-2

Tammy Beaumont guides Dane van Niekerk for a single to reach 50 from 77 balls. It's the 10th time she's passed 50 in ODIs - all of them since Mark Robinson took over as coach. However, when she gets the reverse sweep out of her locker, she's fortunate not to be given lbw from a horrid full toss by DVN which loops up and may have hit her on the body in front of leg stump... though the ball-tracker suggests the impact was outside leg stump. Still, fortune favours the bold.

Like England, South Africa are going to use seven bowlers – it’s time for some leg-spin from Sune Luus, who – rather like England’s Danni Wyatt – has bowled less in recent times as she’s moved up the batting order.

Some proper high, loopy leg-spin from Luus, with plenty of full tosses - straight from the Steve Smith/Kristen Beams coaching manual - and Beaumont nearly perishes on 46 as she slices an edge past the keeper. Slip might have snaffled that up. SA were 84-2 at this halfway point.

Knight drills opposite number Van Niekerk to long-off and puts the fielder under pressure with an early call for two and some good hustling between the wickets. Beaumont, on 44, reverse-sweeps and there’s a comedic moment when Mignon du Preez at backward point turns in a full 360-degree circle as she’s not sure where the ball is going – but does pick it up in time to prevent a run. Fielder and batter both share the joke.

Here's one for fans of Tammy Beaumont to relish.

Beaumont and Knight are starting to find it easier to pick up ones and twos against Tryon than they did against Klaas and Khaka. They need 139 from 162 balls.

But I sense there's a twist or two to come in this game.

Phil Long
TMS statistician

Van Niekerk’s bowling in ODIs is 125 wickets at an average of 18.69. Against England, three wickets at an average of 113.33.

Finally some spin – it’s leg-spinner Dane van Niekerk bringing herself on. But I can’t believe it’s the right move for her to start off bowling round the wicket to the right-handed Beaumont, as anything a fraction outside leg stump takes lbw out of the equation, and Beaumont easily paddle-sweeps her for two. She belatedly switches to bowling over the wicket, but England find easy pickings.

Here's how the England captain was dropped...

It’s all seam from South Africa - an interesting tactic, given that spinner Sophie Ecclestone was comfortably England's most economical bowler.

Klaas is replaced by left-arm seamer Chloe Tryon, fresh from her batting heroics at Hove, although she didn't manage much more than a cameo today. Knight pushes the ball to third man, calls for a second (well, it was her call - she was going to the danger end) as Beaumont dawdles but South Africa throw to that end. Had they thrown to the bowler's end, Beaumont might have been in trouble.

Careful from England, but there's a release shot from Beaumont as the Kent right-hander launches a lofted four straight over the bowler's head, and blasts another towards cow corner for a second-bounce four. She has 35 from 59 balls.

South Africa were 64-2 at this stage.

Alison Mitchell
BBC Test Match Special

I’m glad that the England kit made it to the ground today. About an hour and a half before play, Tammy Beaumont told me that the establishment they were staying at, had not managed to wash their kit in time… Apparently it came back a bit tight, as though it had been put in a quick emergency drier.

South Africa keep going with their second-string seamers, England's third-wicket pair add two singles apiece against Klaas.

Time for drinks - and birthday shout-outs. The TMS team have worked out that Wednesday, 13 June was a birthday for Mignon du Preez (28) and Amy Jones (25), both playing in this game – as well as New Zealand wicketkeeper Rachel Priest (33).

I don't think the Kiwi stumper has ever played an international on this ground - were she to make a big score in Canterbury, the England captain might frustratingly yell "Who will rid me of this turbulent Priest?" - which once had unfortunate consequences in these parts...

Knight dropped on onepublished at 18 overs

18 overs

Eng 61-2

A life for England! Heather Knight chips the ball back to the bowler, Khaka leaps to her right and gets a hand to it.. but can't cling on. Reprieved, Knight adds a two to fine leg.

A key moment - Sarah Taylor is bowled by Khaka.

South Africa are doing well to put the squeeze on England here. Just a single from the over - Beaumont has 25, Knight has one.

Image source, PA

Henry Moeran
BBC Test Match Special commentator

Scoring opportunities are tough for England at the moment. This pitch isn't as quick as we expected.

Knight hasn't faced a ball yet - and she's under way as she squeezes a single through the covers, profiting from a misfield. Beaumont, who's benefited from the odd edge today, helps herself to another single to third man.

Meanwhile, on the England balcony, Danni Wyatt looks engrossed in something - possibly a puzzle book - with Sophie Ecclestone looking on and offering advice. Wyatt, on the card at six, is padded up, while it's fair to say England will be hope Ecclestone doesn't need to strap her pads on tonight.