Image source, AFP

Nice shot from Hales, meeting Steyn's fullish delivery with a straight bat, and a misfield from Kyle Abbott allows England to run three. Now, is Steyn OK here? A grimace of pain and the quick man clutches his shoulder. Has he twinged something? I'm not sure he's going to continue here...no, he's trudging off. Kyle Abbott is going to bowl the rest of the over.

awaywithmedia: Six Bothams beefing.

simon cosgrove: Six balls an over.

The Wordy Gurdy Man: Six Sobers sixes

Hales keeps things ticking with a nudge off his pads for one.

Graeme Swann
Ex-England spinner on BBC Test Match Special

"This third innings always the most difficult to judge for a batting team. If you lose two or three wickets that lead starts to shrink in the mind of the batting team."

England's selectors have tried eight opening partners for Alastair Cook since the retirement of Andrew Strauss, trying and discarding candidates like a picky child working their way through a tin of Quality Street. In Alex Hales, have they finally found a flamboyant strawberry creme to Cook's solid toffee finger? The Nottinghamshire man is off the mark with a lovely flick to mid-wicket.

Image source, Getty Images

Paul Stratton: Might need Elgar to get Bach-to-Bach hundreds to stay in this game.

Elgan Evan Alderman: ‏Elgar was the only one who could deal with Moeen's enigma variations.

Dave 大卫: Not too much pomp but very impressive in the circumstances from Elgar. 

Morne Morkel has dismissed Alastair Cook six times in 11 Tests and he scents blood again here. He's slanting the ball across the England skipper, looking to get him scuttling crabbily across his crease rather than confidently planting that foot to the pitch of the ball. Cook resists temptation then keeps the strike by working a single to leg.

Jonathan Agnew
BBC Test Match Special

Image source, AP

"Hales has to be so watchful of line and length - no ambitious drives. His first-innings shot will be burning away in the back of his mind. He has to show good judgement, get through the new ball."

Cook scampers a single and suddenly Alex Hales is on strike against Dale Steyn. Deep breaths. Hales has a flash at a widish delivery, prompting a look of absolute disgust from Steyn, whose stare could vaporise granite.

Graeme Swann
Ex-England spinner on BBC Test Match Special

"South Africa might be thinking that they are 80 behind so they can't afford to be any further. In the first few overs you should attack, attack, attack."

Morne Morkel takes the new cherry from the other end, and immediately produces an absolute rozzer, the ball pitching on off stump and just straightening past Alex Hales's outside edge. An early warning for the England opener.

Image source, AFP

Steyn misfires with a leg-side delivery which Cook gratefully flicks fine for four to get off a pair. But the radar is soon working again, as Steyn produces a perfect delivery on a fourth-stump which Cook nicks just short of third slip.

Alastair Cook - on a pair - and Alex Hales take guard. Dale Steyn adjusts his field. Here we go...

Quite the chin-stroker for the South African management, I'd say. But for now, they've got more pressing concerns. Their side desperately need quick wickets to stay in the game. Can they get them? Let's find out...

Graeme Smith
Ex-South Africa captain on BBC Test Match Special

"A lot of the selection decisions have question marks over them. Quinton de Kock is a frontline batsman, he's in form, and he's a good gloveman. There are specialist openers in South African first-class cricket with 10,000 runs, yet we pick Stiaan van Zyl as a makeshift opener. I'd love to know the logic behind it."

Graeme Smith
Ex-South Africa captain on BBC Test Match Special

And here's what former South Africa skipper Graeme Smith had to say about it on TMS:

"AB de Villiers' interview this morning wasn't that convincing. It left a lot of doubt. If he is struggling with his workload, it just makes the decision to make him keep in this Test even more ridiculous. My sense is that there's a few rumblings in the South African camp at the moment."

South Africa's star player AB de Villiers has given a less-than-reassuring interview this morning in the wake of rumours that he could retire from Test cricket.

Here's what he said before the start of play today:

"There are a lot of rumours flying around I hear, but for the last two to three years the only talk I've been doing is to keep myself fresh and to have a bit of rest here and there.

"It's always been the most important thing for me to enjoy my cricket. It's just important to look at the schedule moving forward, that's the talk in the camp and for me maybe not to play all kinds of cricket."

"If I play all the IPL games the whole season, I do get a bit tired towards the end of the season. That's the only thing that I've been talking about in the last while. To keep myself fresh and to keep enjoying the game. I love representing my country and nothing has changed."

Hmmm...

Thank you Stephan. It's been an excellent day for England so far. South Africa, on the other hand - well, have you ever seen a number one-ranked side with so many problems? They haven't got a proper keeper, or a decent spinner, or an opening pair. And batters three, five, six and seven have barely made a run between them in Test cricket this year. And you can add to this litany of ailments the beginnings of a very troubling complaint indeed...

Right, after that monster first session, I'm off to get myself a second breakfast. The redoubtable James Gheerbrant is here to take the reins.