Amla is using all of his experience to survive here. He's trying his best to play with soft hands and not to nibble at the ball to serve a catch up to the slips.

When the opportunity arises he's still looking to score with six fours already. Here's one of them...

Hashim Amla does not miss out twice. Too short and too wide from Anderson and first Amla hits the point fielder but the second time he cuts the ball for four.

Image source, Reuters

After the top edge a couple of overs ago, Broad has two men out on the pull to Amla but the batsman is still taking it on. Again the shot is a little up-ish but finds the turf comfortably short of Moeen Ali at fine leg.

Broad is not impressed. He stands halfway down the pitch with his hands on hips. De Kock bears the brunt of Broad's anger as the bowler serves up another beauty.

Matt Harker: The question shouldn't be why De Kock is coming in at No.4 now, but why he was coming in at No.8 before?

Greg Boon‏: Hashim Amla starting to find his rhythm now, great content. This is such an important partnership for both sides.

Paul Baldwin‏: A massive test of Root's captaincy today.

Geoffrey Boycott
Ex-England batsman on BBC Test Match Special

It's a slow surface but unless England take a wicket, the scoreboard will tick along quite quickly now. De Kock is like David Gower at number four. He effortlessly strokes it to the boundary and now Amla is finding his form. Without a wicket, this match could turn to South Africa's favour.

Anderson gets his first look at De Kock but the left-hander is able to get off strike with a push into the leg side. I'd definitely want to be at the other end with swinging conditions and Jimmy Anderson in the attack.

A right-hand left-hand combination for the bowlers to deal with now though and Jimmy strays a little in line.

Stephan Shemilt
BBC Sport at Trent Bridge

Fascinating, engrossing cricket, the crowd spontaneously breaking into applause as Anderson displays his extraordinary skill of making the ball sing. When it isn't going past the bat, Amla is stroking it to the fence.

Henry Blofeld
BBC Test Match Special

Every shot Quinton de Kock plays means something. He somehow takes charge of the game and takes it to the next level.

Wicket-taker Broad again to Amla. Shot! A textbook drive from the right-hander races to the fence.

Broad shouldn't mind seeing that though as he stands and stares with his hand on his chin at the end of his delivery. The ball is doing a bit. Keep it up there.

De Kock gets off the mark with a push into the covers. Here's the wicket that brought him to the crease...

Henry Blofeld
BBC Test Match Special

In conditions like these, there's no finer bowler in the world than Jimmy Anderson.

This is good cricket. Amla rocks back and drives Jimmy Anderson to the point boundary early in the next over.

Anderson hits back, not once but twice going past the outside edge of Amla's bat.

The Trent Bridge crowd get vocal for the first time, roaring on the England bowler. In-swinger on the final ball. Amla squeezes a single.

A great contest.

Interestingly it is Quinton de Kock in at number four for South Africa.

The 'keeper-batsman batted at number eight (a place lower due to the nightwatchman) and number five at Lord's.

Broad came close to dismissing Kuhn on review in his previous over but eventually he gets his man.

Graeme Swann
Ex-England spinner on BBC Test Match Special

Image source, Getty Images

Very good, Stuart Broad! Shorter than the previous over, good pace and Heino Kuhn hadn't made the necessary adjustments so ended up chopping on.

Dr Toerag: Is there a case for simply telling Broad he's not allowed any reviews, ever? Odds are it would help England.

John Pierce: Captain Root, a little green today, too easily cajoled into both reviews.

Christopher Jones: Root needs to be a little stronger on these decisions. Set the tone.

This is not easy for the batsmen. Anderson the record wicket taker on this ground, Broad third on the list.

Amla, playing in his 105th Test, should have the experience to put up a challenge. Another appeal from England as Anderson hits Amla's pad but again that's too high.

Charles Dagnall
BBC Test Match Special

Anderson is swinging it, Broad is seaming it. England expects.

"Catch!"

No chance, way short.

Broad continues and bangs one in to Amla. The South African gets a top edge on his pull but the ball lands way short of Liam Dawson at fine leg.

The sun is out after lunch but the ball is still moving around, if not more so now. Broad beats Kuhn with an in-dipper.

Mike Bell‏: Some of England's reviews are shockers. I'm listening on radio and even I could tell that one from Broad was going over the top.

Tony Bickley‏: What a waste of a review. Always looked high to me.

Greg Boon‏: Early days for Root, he'll learn so let's not criticise him for losing two reviews. Root needs to look to Cook early on.

Image source, AFP

Wow. Jimmy Anderson is good*.

He has just beaten Amla outside off stump with an absolute pearler. It angled in, pitch middle and off and swung away past the outside edge. Groans and hands on heads in the slip cordon.

Amla survives though and picks up three off the final ball.

*understatement of the century