Michael Vaughan
Ex-England captain on BBC Test Match Special

"James Anderson is a wily old fox. He knows how to stay in the game by keeping things tight and then, before you know it, he's taken two wickets and ends the day with figures of 2-45."

Alastair Cook finally withdraws Moeen in place of James Anderson, who has a packed cordon for former Lancashire team-mate Faf du Plessis. Off-stump line, a touch wide, really. Du Plessis leaves alone a maiden.

Michael Vaughan
Ex-England captain on BBC Test Match Special

Image source, Getty Images

"AB De Villiers scored that 30-odd ball century in an ODI here, and he's walked to the middle with a spring in his step today. He's scoring at a run a ball and he clearly likes batting here."

Ooofff. De Villiers fights fire with fire, taking on the previously unplayable Finn with a belting cut shot that thuds into the boundary board with a rapier thrust. Not quite the menace in that over from Finn.

Michael Vaughan
Ex-England captain on BBC Test Match Special

"Looking at the way Finn has bowled, Morne Morkel will be a handful on here."

Still Moeen. Any chance of some pace, captain? Du Plessis, who I think may have been given a gob full by Finn at the end of the previous over, chews his gum and defends from the crease. It looks much more preferable to be facing Moeen than Finn at the moment. 

Michael Vaughan
Ex-England captain on BBC Test Match Special

"What an over that was from Steven Finn. He was too good for Faf du Plessis. As a batsman, you are just relieved that you're still out there."

Henry Blofeld
BBC Test Match Special

"Goodness me, how is Du Plessis still there?"

Image source, Rex Features

Steven Finn really has been England's most potent threat in this series and produces another rozzer to leave Du Plessis groping like a man looking for his keys in a darkened room. Angle, pitch, nip away. And again! How has that missed? Someone check that the gap between the stumps isn't big enough to fit the ball through.

Beth Jakubowski: Adopting the old under-the-desk phone-checking method after being too bold and sitting at the front of the lecture theatre.

Still Moeen - I'd really fancy another pacer here. The sky is just turning blue, the Wanderers in enjoying increased sunshine. Like pagans at Stonehenge, the Barmies worship the sun, all trumpet and song.

Henry Blofeld
BBC Test Match Special

"AB de Villiers is uncertain, Steven Finn has made him uncertain. He knows he's got a fight on his hands."

This track is a real snake pit. Every so often one rears its head to spit at the batsman. Finn gets a kicker to jam the handle of De Villiers. With the skipper hopping around, Finn flashes his maniacal smile. Shades of Curtly Ambrose. Sir Curtly, as we should call him now. 

Tom Girling: Bairstow on track for 10 dismissals... from 10 different bowlers?!

Still the spin of Moeen. I know he's got the wicket, but would England be better off with pace at both ends? Du Plessis gets off the mark with an edge past slip, the defends to defy the three catchers lurking around the bat.

Geoffrey Boycott
Ex-England batsman on BBC Test Match Special

Image source, Rex Features

"This will be interesting for AB de Villiers. He's just lost his second best batsman and he's seeing the ball is moving around. It could go either way now. Two more wickets for England and it's not looking too clever for him."

Image source, AP

South Africa have lost two wickets for 10 runs and are now up against it. Faf du Plessis joins AB de Villiers in a bid to stop the rot. Even the sun has come out to shine on England's resurgence. Looking again, that ball to get Amla really was a rozzer. It pitched on middle and moved away to square the batsman up. There wasn't a great deal that Amla could do - in fact, a lesser player might not have been good enough to edge it. 

Henry Blofeld
BBC Test Match Special

Image source, Getty Images

"It was a fine piece of bowling and brilliant from Steven Finn, who has been the best England bowler today. England are all pretty pleased with themselves now."

Geoffrey Boycott
Ex-England batsman on BBC Test Match Special

"That was a gorgeous delivery. He pitched it up, the ball left Amla and the batsman didn't transfer his weight forward well enough. Finn deserved that. This is a good moment for England."