Crawley adds another run to the England total with a quick single to backward point. Every run off the bat is really having to be earned.

Rabada gifts them an extra from what should be the last as he can't keep foot behind the line.

That proves costly as a thick outside edge from Bairstow goes to ground quickly, gets through the slips and is away for four.

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

There is no substitute for genuine pace at this level. With high-pace bowling, the teams that tend to deal with it better are those that have it in their arsenal, like Australia.

Nortje is cranking it up again as he bowls to Bairstow. The England man is hit on the body by the penultimate delivery before hanging his bat out tentatively at the last.

Bairstow can be mightily relieved that he didn't nick that. It was not a good shot. Nortje's pace is causing real problems again.

Jambarrell: Weird how Bazball has made Crawley half as aggressive as he used to be while everyone else becomes more aggressive.

A boy called Mick: Looks like Zak Crawley is carrying this team.

Thanks, Tim. It should be a very interesting passage of play through to the end of day one.

South Africa's pacers have got their tails up and England are battling to hold onto the advantage given to them by their bowlers.

Will there be any more wickets in this final hour? Can the new-look Zak Crawley make it through to the close with his wicket still in tact?

My colleague Sam Drury will guide you through the until the close of play.

Kagiso Rabada continues and Jonny Bairstow scrambles a single off his second ball. That was a little uppish and not entirely convincing.

Zak Crawley in watchful mode again as he sees off the next five without fuss, deciding when to defend and when to leave.

Ohh err, that Zak Crawley cover drive which had been lurking in the back of the England opener's locker is brought out as he swishes at one from Anrich Nortje. He does not make contact, though.

An expensive over from Nortje after five wides, four byes and two runs off the bat. Jonny Bairstow is off the mark, too.

A reminder here of how Ollie Pope was dismissed...

He took 12 runs off an Anrich Nortje over, including back-to-back boundaries...

...but the next over was then done for pace by Nortje.

A quick drinks is already over. We have about an hour of play left.

Steven Finn
Former England bowler on BBC Test Match Special

Perfect seam position from Rabada and Joe Root will wonder whether he had to play it. South Africa will now be sensing blood.

Simon Mann
BBC Test Match Special

Juggled it and caught, Root is on his way and the bowling change has worked. This game is galloping along.

We're right in the balance with this game now.

Simon Mann
BBC Test Match Special

It was a full, swinging delivery and for a moment I thought Root was in trouble. He might have been had he missed it.

Kagiso Rabada back into the attack as Dean Elgar dispenses with the spinner. Joe Root eases a tricky delivery which had a hint of swing off his legs for a couple.

Andy Zaltzman
BBC Test Match Special statistician

In the two overs Nortje has bowled, he's averaged 89.7mph. His fastest ball at Lord's was 96.6mph, his fastest here has been 92.2mph.

Zak Crawley is seven off 34 balls. More Boycsball than Bazball, but crucially he's still there. He hasn't really offered any chances really, either. That cover drive has been left in the locker for the time being.

He's happy to see off five dot balls from Anrich Nortje.

Steven Finn
Former England bowler on BBC Test Match Special

Joe Root is so light on his feet. He's a tall man but he never gets caught on the crease.

Joe Root pushes on to the front foot, then transfers his weight on to his back foot to work Keshav Maharaj away off his legs. He pinches the strike off the final ball of the over.

Daniel Norcross
BBC Radio

Root latched onto that very quickly and collects his first boundary.