Stacy Lackay is the new batter - remarkably, we have the first extra of the innings from the first ball of the 17th over (bowled by Kerr), and it's a leg-bye. Next ball, it's deflected behind and it's two more leg-byes. And extras are genuinely like buses - you wait 17 overs for one, and then you get three in a row as Kerr sends down a legside wide.

A seventh bowler - it's Anna Peterson, an off-spinner from Auckland who has a T20 international hat-trick on her CV. She nearly runs out Du Preez when she deflects Van Niekerk's shot onto the stumps at the bowler's end - but the bails remain resolutely in place. And would you believe, the same thing happens on the last ball , this time from Peterson's underarm throw - this time the bails are off and they're going upstairs!

Natalie Germanos
BBC Test Match Special commentator

If they were batting first, with 116 from 15 overs, you'd think they were doing well. Unfortunately, they're chasing 217.

It's been a good stand for the Proteas, but their running between the wickets hasn't been quite as good as New Zealand's - as there are a couple of occasions this over when they take one when two looked possible.

Van Niekerk falls over trying to shovel the last ball for four through fine leg - it's an expensive first over from Rowe, 14 from it.

Phil Long
TMS statistician

This is now South Africa's highest fifth-wicket partnership in T20s.

Image source, Rex Features

Time for Hannah Rowe, one of several Kiwis who've not been needed to bat or bowl today, to come on as the White Ferns' sixth bowler. The medium-pacer sports a blonde ponytail nearly as long as that of Australia pace bowler Holly Ferling - but doesn't have anything approaching Ferling's pace, as Van Niekerk slams her for a couple of fours - despite the best efforts of Suzie Bates getting a hand to the second one.

Image source, Getty Images

Van Niekerk guides the recalled Hayley Jensen for four, while a single brings up the hundred for her side.

Meanwhile, some schoolchildren in the stands seem to be having the time of their lives. Perhaps their homework has been cancelled?

Lydia Greenway
Ex-England batter on BBC Test Match Special

All South Africa can think about is trying to get their run rate up as much as possible, as it could have some bearing later in the competition. And it's a tough gig for them playing two T20 games in succession.

Image source, Getty Images

Sophie Devine, who has bowled nearly as well as she batted earlier, keeps it tight for the Kiwis - though Van Niekerk eventually manages a boundary when she rocks back and uppercuts a four to third man.

Raf Nicholson: I suspect England are watching this with glee - South Africa are going to be thoroughly demoralised going into today's second game.

Van Niekerk slogs Kasperek through mid-wicket for four - that's 13 off the over, but the required rate is now north of 16.

Image source, Rex Features

Phil Long
TMS statistician

All the scoring shots in this innings before this over were ones and fours. In the New Zealand innings we had twos, threes, sixes and a five.

CLOSE!published at 11.2 overs

11.2 overs

SA 81-4

Du Preez tries to hit Kasperek over the top, mid-off Hannah Rowe dives towards it but can't take the catch. But she has no chance when Van Niekerk comes down the track and hits one over Rowe's head for four.

Lydia Greenway
Ex-England batter on BBC Test Match Special

This is quite an uncharacteristic innings from Van Niekerk, who's normally a clean striker of the ball.

Image source, Rex Features

Isabelle Westbury
Former Middlesex captain on BBC Test Match Special

I think Van Niekerk may have done like Tim Paine did at Trent Bridge yesterday - looked up, thought "send them in" and then been on the end of a record batting total.

Tahuhu off after three overs, Sophie Devine has had a change of ends. Former skipper Du Preez hits one into the Taunton skies over mid-wicket... but it drops between two fielders. Current skipper Van Niekerk has less success at beating the infield - and is nearly knocked over by a bouncer with which she can't connect.

Lydia Greenway
Ex-England batter on BBC Test Match Special

It's not a bad score in terms of T20 cricket, especially at this ground where the average score is 132.

It looks like the damp atmosphere may be making it difficult for the spinners to grip the ball - Kerr is wiping the ball with a gleaming white towel between deliveries. We've reached the halfway point of the innings.

South Africa have picked up a little, but the required rate is in excess of 14.

Kerr from the River End - and Mignon du Preez shows no respect to the youngster, pulling her fourth four in the space of six balls.

Image source, Rex Features