6th over: Australia 13-1 (Head 3, Labuschagne 2) Head gets up the other end where he’d want to be. Jansen then shifts to round the wicket to Marnus, looking to angle it into his stumps. But Marnus is tidy and keeps him out.

Here’s a nice message from George van Zijl.

“Greetings from Potchefstroom. I’m so glad I can actually follow the OBO with skin in the game. Just because the OBO is so good as reading material I even started following the Ashes, which I think is a ridiculous sporting event as it just breeds arrogance from whoever the winner is, when more often than not it is being played by a mediocre team vs Australia (This will probably age terribly later this year when England tours South Africa, in which case I apologise in advance to Bavuma and co). Anycase, thanks for the coverage of this series and all others covered by the OBO, I have spent hours otherwisely productive reading the cricket, philosophy, music and whatever discussions are on.”

That very much captures the spirit of it, George, thank you. And I agree about the Ashes, which often don’t have the quality to deserve the kind of billing they receive.

That goes down in the Hall of Ignominy for Australian cricket, with a fair few entries against South African sides. All out 47 in Cape Town, all out 85 in Hobart, and this one here, where any half reasonable batting effort today would really have put a South African win out of reach. Instead Australia have burned one whole innings and remain 326 runs behind.

South Africa will be buzzing. Jansen was fierce, ending with 5 for 33. Mulder chipped in with 2 for 14, while Rabada topped and tailed the innings with 2 for 33. Nortje had time for one wicket, but won’t take any more in this match, off the field injured.

So now we see a rare sight in modern Test cricket: the follow-on enforced. South Africa could have batted for a couple of hours to rest their bowlers, pushed the lead back up past 400, and then had a burst before stumps with a full day to bowl tomorrow.

But with weather and light a factor here, they’ve decided to try to keep the Aussies down while they’re down, and have at them again immediately with a new ball. That’s a big call when you’re a bowler down, but they do have Mulder, so they still have four frontliners to work with.

They’re 1-0 down in the series, so they have to take some risks. Either approach would have an element of danger.

42nd over: Australia 98-9 (Cummins 7, Hazlewood 1) Just one wicket to go for South Africa. Hazlewood wafts, then again, and gets a run at his second attempt. Cummins is looking to score anything while he still can, and shapes to clean out Rabada over long on, but the length is nowhere near full enough, and it’s a fresh-air shot.

What a working over. The pitch seems to have developed some little ridges that are helping the ball to move a touch, and it’s hard work even at Mulder’s more modest pace. Smith has getting more physio attention for this stiff neck. It’s bothering him, and he’s not moving freely. So the second ball of the over jumps, beating Smith and the keeper for four byes. The third ball cuts in, hitting Smith in the stomach. And the fourth, he’s nowhere near it. Distracted perhaps by the jagging around. He’s jumping to play it, he’s bringing his bat across the line of it, but that ball isn’t short enough to need to jump. It jags in again, stump height, and takes the top of off.

That’s the last big fish in the lake. Now to scoop up the minnows.

40th over: Australia 92-7 (Smith 28, Cummins 7) Jansen to Smith, who nudges a single into the off side, and that is 11,000 runs in Test cricket for him.

Joins the former XI of Border, Jayawardene, Chanderpaul, Lara, Sangakkara, Cook, Dravid, Kallis, Ponting, Root, Tendulkar, making them a dozen.

Cummins is doing more of the scoring, though, pushing a brace and then clipping four square of the wicket.

Three slips and a gully for Jansen, and Webster feeds them for Jansen’s fifth. Brainless shot again from an Australian player, a big forcing drive with no footwork, movement going nowhere, weight leaning back, thus a very low chance of connecting convincingly. Instead he edges, and Markram at second slip dives to his left in front of first slip to hold the catch. This is bordering on an epochal collapse.

37th over: Australia 84-6 (Smith 27, Webster 12) DRS reprieves Webster! Given out caught behind off Mulder, the South Africans think that they are right amongst the pigeons in their feline forms, but the moment is retracted. The ball beats the outside edge and just beats the off stump, Webster saying that he thinks it clipped the bail. But DRS shows no spike from bat or stump, and the decision is overturned. Webster celebrates by blazing four through the covers, off a no-ball as well.

35th over: Australia 73-6 (Smith 26, Webster 4) Nortje is out of the game. He’s wearing the full training kit on the balcony. They’re saying it’s a groin strain. Jansen had one of those yesterday when he had his fruitbowl turned into a smoothie.

Mulder joins Jansen as the post-lunch bowler. Presumably now Bavuma wants to go Jansen, then Rabada, rather than using them both up in tandem. Mulder is less of a threat in these conditions, more an honest operator, and he tries to stay on Smith’s off stump. Given some of Smith’s wild shots though, it might not be the worst idea to feed that wider line.

Gervase Greene writes in. “Not judging anything on one innings, or even one series, but isn’t it about time we had a sensible discussion about whether Head remains as opener As I recall, originally the main argument for his opening was to balance Uzzie Khawaja’s important but increasingly stolid presence. Some miracle innings notwithstanding, fact is I would love to see Trav coming in tonight at 5 or 6. But he’s already gone, as he so often has been in the past two years. The issue is not so much the perennial Australian debate about ‘can he fill the opener spot?’ but whether we are really getting the best out of Trav while he’s with us. He is a one-in-a-generation talent, a rare diamond in the rough, and I fear we are chucking a lot of his remaining time in the big league away.”

That was exactly my concern after the wild hundred at Perth. It was so much fun that of course everyone wanted to let him keep doing it, and it did work through the rest of that series, but it never felt like a long term solution, especially against better bowling in foreign conditions. Head further down the order was someone whose style had a better chance to work; opening you’ll always have a greater attrition rate. The classic taking from a strength to look after a weakness.

High octane session, starting intensely and ending intensely. The South Africans have taken five wickets and given away only 66 runs, adding to their late wicket last night. Rabada has been unbelievable, and mostly what’s hard to believe is that he only has one of the wickets. Jansen has four, and has bowled just as well. In the meantime, Nortje is off injured having bowled 3.3 overs.

The Australians are in all sorts. Bad shot last night from Maddinson, who you can’t expect much from. Basic error from Head, bad technique from Labuschagne plus a stunning catch. Boland as expected from a night guard. Renshaw got a beauty, Carey played a shocker. Smith has looked terrible, but is somehow still there. His team desperately need him to carry on. Still 156 from the follow-on.

32nd over: Australia 67-6 (Smith 24, Webster 0) Not that Smith is having an easier time than anyone else. Where was this sense of threat from the Australian bowlers yesterday with an older ball? Jansen has Smith jumping to defend, then jumping out of the way. Next, a swish outside off stump, then a loud appeal for a ball that cuts in and thuds into pad. It’s just going over the bails on the projection, and Bavuma correctly guessed that, gesturing height to his teammates. Smith pushes a run to cover fifth ball. One over to go before the break.

31st over: Australia 66-6 (Smith 23, Webster 0) Interesting byplay here. Not that you’d need to shield Webster from strike, but I wonder whether a cricket strategist would want the set Smith to take a single first ball of Rabada’s over, five minutes from lunch. It very nearly brings about Webster’s wicket, the ball a beauty that seams away slightly, similar to the way that Cummins does it, and so nearly takes the edge of Webster’s bat.

There’s the big one! In the context of this series as it is, bigger than Smith. And that’s a brilliant piece of bowling from Jansen. Has Renshaw leaving, leaving, blocking, then suddenly pulls the length back, same line, Jansen using all of his height in getting the ball to jump at the batter, and while Renshaw is also tall, he can’t ride that bounce. Gets his hands up to try, but the ball takes the shoulder of the bat and flies low into the gully where Harmer takes another very good one, low down.