Alex Hartley
Former England bowler on BBC Test Match Special

Having watched Maia Bouchier, you would not think it was her Test debut. She looks comfortable and calm at the crease and hasn't gotten bogged down because Heather Knight is going at a lesser strike rate.

Bouchier looks very much at home in Test cricket.

Kevin Howells
BBC Test Match Special commentator

I don't want to take away from her half-century, but Maia Bouchier got a little bit of fortune there. She deserves it but she should have been caught.

Maia Bouchier looks frustrated with herself after that near miss in reaching her fifty but it's been a good knock from the England opener on debut.

A single later in the over also brings up the fifty partnership with Heather Knight.

50 for Maia Bouchierpublished at 25.2 overs

25.2 overs

Eng 102-1

Tumi Sekhukhune is into the attack for the first time as lunch approaches - but Maia Bouchier puts her second ball over long leg for six!

That brings up a half-century on debut for Bouchier from 71 balls.

Should she have been caught in the deep there, though? It looks as though Marizanne Kapp was in position to take it but the ball went straight past her. I don't think she even got a hand to it.

Alex Hartley
Former England bowler on BBC Test Match Special

It's hard to say where the game is as it's still early on. Maia Bouchier is really impressing me and you would never know it is her Test debut.

I would love South Africa to try something, it feels a little bit easy for England at the moment.

Good placement from Heather Knight, getting a good stride in and driving Ayanda Hlubi through extra cover for four.

It isn't brilliantly timed but with such short boundaries and a quick outfield, the ball wins the race to the boundary cushion.

Kevin Howells
BBC Test Match Special commentator

There is quite a bit of wind picking up now and there looks like storm clouds are coming in. But at the moment we play on.

The last thing you want in a four-day Test is a rain delay.

Srinivas Vijaykumar
Cricviz analyst

Playing straight down the wicket is Maia Bouchier's strength. In her international career a third of her runs (33%) have come in the 'V' down the wicket. Of the players with 1000+ runs for England since 2012, only Sophia Dunkley (39%) has scored runs more often straight down the wicket.

Maiden from Nadine de Klerk, who is getting the ball to shape away from the England right-handers.

Maia Bouchier drives nicely late in the over but the cover region is packed and she can't find the gap.

Alex Hartley
Former England bowler on BBC Test Match Special

Ayanda Hlubi looks frustrated and Heather Knight has got so lucky. She looked around straight away to see if it had hit her stumps.

Marizanne Kapp's second spell is a very short one - just two overs - so she'll remain wicketless in Tests for now, with Ayanda Hlubi back on.

So close! The last ball of the over nips back to find Heather Knight's inside edge, brushes the back leg but just misses the stumps.

Not only that, the ball runs away for four. A moment of good fortune for the England captain.

Srinivas Vijaykumar
Cricviz analyst

Image source, Getty Images

Marizanne Kapp is yet to a take a wicket in Test matches, playing in her fourth game since making her debut in 2014. She picked up her first ODI wicket in her eighth game, back in October 2011 - dismissing Danni Wyatt-Hodge, here in South Africa at Potchefstroom.

Alex Hartley
Former England bowler on BBC Test Match Special

It's a strange thing that the Test match is only four days, it means most matches are usually a draw. The more women play Test cricket the better they will get.

But then, there is campaigning for men's Test cricket to be four days so it's all changing.

Full and floaty ball outside off from Nadine de Klerk to end the over and Heather Knight unfurls an elegant cover drive... but can't beat the in-field.

A little under 20 minutes until lunch. It's been a good session for England so far.

Marizanne Kapp is giving nothing away on her return to the attack and, even with the free-scoring Maia Bouchier on strike, gets through a maiden.

South Africa have done a good job of slowing England down in the last half an hour or so.

Alex Hartley
Former England bowler on BBC Test Match Special

It's been a strange passage of play. Heather Knight is sitting very happy at the moment, she's not thinking about scoring every delivery.

Maia Bouchier on the other hand is scoring very nicely.

After a bit of a slow passage of play, there is a bit of excitement in the Nadine de Klerk over.

Firstly, Heather Knight plays and misses at a ball wide of off and is no doubt relieved not to have got anything off it. That was loose from the England captain.

She quickly brushes it off, though, and whips the next ball through the leg side for four.

Daniel Norcross
Test Match Special commentator

It seems a pretty slow surface, there's not a whole lot of life in it. We haven't seen if the ball will turn or not yet which will be an important point in the game.

Marizanne Kapp returns to the attack and it is a tidy over as you'd expect.

Two singles from it.

Meanwhile, the frequency with which the TV are showing pictures of trees being blown all over the place by the wind with threatening-looking clouds above probably isn't a good sign...

Ffion Wynne
BBC Sport cricket writer

South Africa's bowlers have started quite disciplined to Heather Knight. She is just having to support Maia Bouchier through her innings which is a role she's not used to.

We have the more experienced player guiding the Test match debutant and if Knight can maintain this patience she will have had a good morning.