Phil Tufnell
Former England spinner on BBC Two

I've thoroughly enjoyed the morning session. Great Test cricket. Ben Stokes has chosen his moment to assert his authority. He's batted beautifully, and had good support from Ben Foakes as well.

The fifty partnership comes up between Stokes and Foakes as the latter works a ball off middle and leg, towards mid-on for a single.

It's been a very useful stand for England. They're looking fairly comfortable now but they came together in the middle of that ferocious spell from Nortje with the ball reversing viciously.

Kagiso Rabada is back for another burst before lunch. South Africa need something from the leader of their attack.

Vernon Philander
Former South Africa fast bowler on BBC Test Match Special

That is a brilliant shot. He's got such good balance when he plays against the off-spinner. There's a lot of South Africa fielders on the leg side, and Ben Foakes has pierced the gap superbly.

Superb from Foakes. The ball is a touch too full from Harmer and Foakes whips it through mid-wicket with real authority.

Right out of the middle of the bat, all along the turf for four. With half an hour to go until lunch, England will be pretty satisfied with their morning so far.

Feast your eyes on this: the first of two glorious straight drives for four from Ben Stokes off Lungi Ngidi.

With the ball getting older - Stuart Broad was rather scathing about this batch of Dukes balls yesterday - now is the time you want to be batting.

The shine and the hardness of the ball is gone, and it is time to cash in as the batting side. Stokes and Foakes look to be doing just that.

Vernon Philander
Former South Africa fast bowler on BBC Test Match Special

There's nothing wrong with that from Ben Stokes. He's come down the pitch but is fully in control of the shot.

That's glorious. Stokes is down the pitch to Ngidi again and it's another beautiful, beautiful straight drive.

Nothing reckless about that, just pure class. Quite rightly, he holds the pose as the ball races away to the fence.

Here is that moment when Stokes went down. It didn't look good but, thankfully, he has been able to continue and is doing a good job of disguising any discomfort he might be in.

Stokes is down to sweep Harmer again. The ball goes all along the ground this time and he has to settle for one.

Meanwhile, Foakes is ticking over nicely now and skips down the track to push a single from the last.

Vernon Philander
Former South Africa fast bowler on BBC Test Match Special

It's been real good stuff from England ticking over the scoreboard, slowly building up something a lead. They need to fight to get themselves back in the series. Ben Stokes is the key player here, you feel. His knee is a bit of concern, although he seems to be running okay between the wickets.

There are some oohs and ahs from the South African fielders as Stokes prods forward and gets a thick inside edge. It goes through his legs and he gets a single. It could have ended very differently though.

Foakes then adds two from the last, guided wide of gully to grow the England lead that bit more.

Stokes is on the charge. He's moving well enough to shimmy down the pitch to Ngidi and drive the ball straight back past the bowler for four.

That might be the shot of the match so far.

Just a couple from Harmer's over but the good news for England is that one of them is a quick single for Stokes. He hurried through and looked comfortable enough.

Stokes gets through another maiden from Ngidi. There is one half-hearted appeal for lbw as the England left-hander digs out a yorker.

Verreynne behind the stumps seems convinced that it was boot/ pad first but none of his teammates are giving that theory much credence. No review.

Vernon Philander
Former South Africa fast bowler on BBC Test Match Special

England have fought hard to get themselves into a position where they can dominate this Test match. Ben Stokes is a key part in trying to make that happen, so a relief for England fans to see he is up on his feet again.