It'll be a grim old chat over the soup and sandwiches for the Aussies. A disaster of a session. They're going to be absolutely pelted by everyone with a passing interest in the sport. South Africa, though, this has been a historic couple of hours for this side. On the mat early in the series, lost that first Test in humiliating style, and they're been fierce ever since.

26th over: Australia 60-7 (Green 25) Last ball of the over, last ball of the session now as well, and Harmer strikes again. Starc has played with some heart, declining runs and doing his best in defence, but a ball spearing in at his pads causes him concern, thrusting the bat at it while trying to get his feet out of the way. His ankle rolls slightly, he gets the full face of the bat onto the ball, and from there it thuds into his pad and up into the air. Short leg is waiting under it. Harmer has 3 for 5!

25th over: Australia 59-6 (Green 25, Starc 0) If indeed Green is avoiding spin, then South Africa make sure he has to face some. Markram comes on for a bowl. Green drives two runs powerfully to deep cover, then is happy to take a single. So maybe the issue was about Starc facing pace early.

David emails in. "Looking back on this Test, the Australians started off on the wrong foot and it was only Mitchell Starc's extraordinary intervention at the end of the first day that allowed them to be in front at all. Should never have bowled first with the attack selected, why would they volunteer to face Harmer and Rabada on the final day? Putting their head in the lion's mouth because of concerns with the batting. Think a large part of that has been insisting on playing Marnus for 12 months past when his form warranted. Has lead to a permanently weak and makeshift top order. You reap what you sow. Time to bite the bullet and reshape the team."

This batting order has been jumbled and out of sorts for a while now. Opening, three, the confusion between six and seven, have all been problems.

24th over: Australia 56-6 (Green 22, Starc 0) Harmer is teasing Starc's off stump. Two back-foot defensive punches playing leg side of the ball, trying to keep his pads out of the way, but it leaves the pegs open, and twice Starc misses that shot and Harmer almost bowls him. The last of the over Starc leaves, and Harmer almost bowls him. He'll get the line right sooner or later, surely.

23rd over: Australia 56-6 (Green 22, Starc 0) I'm neglecting your emails, sorry, things just got too hot in the hot seat. Green takes two runs into the deep, knew he'd have time to get back. More extras for Australia, they're only a boundary away from becoming second top-scorer, as Coetzee bowls with wild bounce that clears Green and swerves late in the air past the keeper.

22nd over: Australia 50-6 (Green 20, Starc 0) Harmer with big turn again, past the edge of Starc's bat and away for four byes. Yep, they're dead-batting now. Starc twice hits to deep point and refuses to run. Is that because he doesn't want to face Coetzee, or Green doesn't want to face Harmer? Surely Harmer is a massive threat to a left-handed lower order player.

21st over: Australia 46-6 (Green 20, Starc 0) Coetzee bowls a maiden. Not many of those for him in this match. What's the plan for Green from here? Just bat long? I said before play that the draw was unlikely, well it's absolutely miles away. Perhaps though it's the only chance Australia have.

20th over: Australia 46-6 (Green 20, Starc 0) Another catch goes down! Starc edging Harmer to slip this time, it travels quickly, but Markram isn't really to blame there, because that ball his clipped the keeper's glove on the way. Markram is actually moving his hands into the correct spot to take that catch on a fine angle behind the keeper, then the change in direction confounds his efforts, and he nearly wears that ball in the face.

19th over: Australia 46-6 (Green 20, Starc 0) Gerald Coetzee, the ultimate afterthought bowler today, finally gets a roll. Green edges him away for a boundary. Lots of pace to work with.

18th over: Australia 42-6 (Green 16, Starc 0) Harmer always shaped as the main day-five influence, then wasn't required as the first four wickets fell. Now he's irrevocably shaped this match with a double strike in the 18th over.

No worries, Coop. Your second Test, would you mind coming in at seven with 246 runs to get on day five? Can't expect much from the junior player in this situation. Harmer gives it flight, offers him a drive, Connolly accepts, and some turn away from the left-hander takes the outside edge.

Capitulation. That is all this is, now. This Australian team is under a fair bit of scrutiny back home already, and it's going to become intense given the way they've thrown this away.

A leg-side nick, leaving a ball that was hitting, a stupid drive against the new ball, a self-inflicted run out, and now a reverse sweep to short fine leg. This ain't a T20.

17th over: Australia 42-4 (Green 16, Carey 2) Jansen through another over with only a single added.

16th over: Australia 41-4 (Green 16, Carey 1) And so. South Africa were 40 for 4 in Gqeberha, and won. They were 40 for 4 in effect during their third innings here. And now Australia are 40 for 4 in the chase. It's probably not going to work out for them, though. Carey makes it 41 with his first run.

What have you done, Cam Green? Never a run in that, no need to be pinching singles like it's the last over of a one-day international. Green pushes Harmer away into the off side and takes off. Inglis does the team thing and responds. He's quick, but not that quick. The ball limps short leg, barely moving, and Ackerman in that position just has to turn around, run a few steps, pick it up and spin back, firing it over the bails. Rickelton smashes his gloves down on top of the stumps, finding Inglis well short.

15th over: Australia 39-3 (Green 16, Inglis 3) Inglis plays a crisp pull shot, only gets a single for it, but nicely played. And then Green is lucky to survive again! South Africa lose a review into the bargain. Jansen around the wicket angling in, Green pushes forward, and the slightest inside edge, into his front pad, which then deflects the ball millimetres wide of his off stump. The South Africans think it was pad first, so they review. Thus, Green was almost caught behind off the inside edge, almost lbw, and almost bowled, and because of that South Africa lose a review and the batter profits by four runs, because the keeper was too busy appealing to stop the nick going by to the rope.

14th over: Australia 34-3 (Green 12, Inglis 2) Drinks break there, then Harmer continues, and he drops Green off his own bowling! That would have been immense for South Africa. Green drives back straight, but mistimes it, in the air and low to the bowler's left hand. Harmer gets down and almost fingertips it, maybe touches it into the ground. He's scooped up a few in this series at slip, and missed one earlier in this match, but now that one goes down from his own work. I have the feeling that more chances will be coming from Harmer, though.

13th over: Australia 32-3 (Green 10, Inglis 2) Jansen continues over the wicket, they've got short leg in place, and that man is in play with the left-armer's angle into the right-hander's body. Green plays a couple down not too far away from the catcher. Then gets a run into the covers. He has crawled into double figures, staunch resistance so far.

12th over: Australia 31-3 (Green 9, Inglis 2) Here comes Harmer, and he will be key… right on the money first ball! He was picked in this side to bowl to the left-handers, but the big patch of rough is outside the right-hander's off stump, and he has two of those to deal with. Lands the ball in that rough and it turns sharply into Green's pad, just outside the line of the off stump. Nearly lbw. Green manages to drive a run to get off strike though.

11th over: Australia 30-3 (Green 8, Inglis 2) Into the leg side goes Inglis for a single, doubling his score. Green finds another. He's looked very calm so far. Hey, they're 10 percent of the way to the target, why not?

10th over: Australia 28-3 (Green 7, Inglis 1) Things are starting to settle, as Mulder bowls a maiden to Green. This innings may quickly get down to a grind. But South Africa have the new-ball incisions that have set them up to have the best of that grind.

"Oh no! I started this email at 0/0 but now it's 2/5 so it's probably irrelevant now," says an even less relevant Lachy Zammit. No, that's not true Lachy, you're always relevant. "I'm trying to work my way around StatsGuru, looking up famous Australian chases and assessing how experienced those top sevens were. It turns out that searching through stats by yourself is tricky business, so I haven't worked anything out. What can we say about the importance of the experience in a batting line up for an intense chase?"

Unfortunately there's no stats category to define how many matches players had previously played at the time of a certain match. The best you can do is find the highest chase scores list, open those scorecards, and eyeball it: see the notable names and the year and figure out how far into their careers they were.

But it's not necessarily down to experience. Kyle Mayers made a double ton on debut chasing nearly 400. Those great Australian teams didn't chase a lot of big fourth-innings scores (I remember Hobart 99, and a couple here in South Africa shortly afterwards). They tended to beat teams by big margins, and not need to chase big.

9th over: Australia 28-3 (Green 7, Inglis 1) Rabada continues. Such a smooth mover, delightful to watch. Josh Inglis doesn't look bothered, after his first-innings century. Works his first run to midwicket. Green takes another.

Ewan Glenton's email was written before Head's wicket, but is all the more apt now. "Obviously Travis Head's place in the team isn't in doubt, but presumably there's a bit of debate about whether he should be opening, or made best use of further down the order. Surely a Test opener should be capable of reigning things in when required (I seem to remember Warner - similarly branded an attack-dog opener - was well able to do that). The fact is Aus don't need a 'Travis Head special' today (fun though it would be, of course): they can win this easily scoring at much less about, what, 3.5 an over? And given the rest of their batting isn't very reliable, to say the least, losing him much before lunch would put them under a load of pressure."

You have not written an untrue word, Ewan. Killing the chase early can be a good move chasing 200 on a flat track on day two when the other mob have collapsed twice. Less so chasing close to 300 on day five when the other mob have played really well.

8th over: Australia 26-3 (Green 6, Inglis 0) Mulder comes on early, this is interesting. Green isn't shutting up shop, either, which is probably a good move. Drives him with a lot of punch through the covers, four.

Premonition from David Blackah a few overs ago. "This all swings on Travis Head. If he gets going we are home. I would hate to see it come down to the GOAT holding up an end to save a draw. As the great Rex Mossop used to say, elan elan, toujours elan!"

It has swung on Travis Head, and not Australia's way. He's gone home rather than getting anyone home.

7th over: Australia 22-3 (Green 2) And that might be the ball game! What an over, it's a journey from start to finish. Walk through it with me.

A defensive shot from Green gets him a run into the off side, then Rabada goes back to tormenting Head. Seam movement again, angled in at Head from around the wicket, then it decks away. So noticeable that this ball is seaming where barely a delivery moved sideways off the surface in the first four days. Head gets control of himself next ball, and rather than throwing the bat he places it, driving in front of point in lovely style for four. But that's as far as his day will go. Rabada goes yorker, curling in, and Head just about keeps it out, lots of toe of the bat, which twists in his hands. Then the sixth ball is the telling blow, pushed a little wider, a fuller length that yet is not a half volley, and Head drives because Head drives, big edge, and Jansen in the gully buckets it in front of his face.

Rabada has three of three, and 350 in his career.

6th over: Australia 17-2 (Head 10, Green 1) Jansen thumps a ball from over the wicket into the middle of Head's pad, on an angle so there's no dismissal risk, but it's such a hefty blow that it takes a lot of pace out of the ball, keeping the resulting leg byes to two rather than four. That's the only good news for Australia right now.

Muhammad Najib writes in. "Who says Test cricket is dead? It's keeping the lights on here in Seattle. This final day reminds me of several iconic matches at once: Ashes 2005 second and third Tests both; Ashes 2006 when Mike Hussey scored the winning runs, then Travis Head's century in the last Ashes. Whatever happens happens. It's a day of pressure and whoever handles pressure best… All I want to see is a Marnus ton, so we keep listening to his onfield commentary with Gaz bowling on the other end."

Your final wish arrived a bit late to help the dynamo, sorry.

5th over: Australia 15-2 (Head 10, Green 1) Travis! You cad. Another whistling cut shot that meets nothing but nitrogen and oxygen molecules. Misses that one, the Rabada gets it to seam again and beats a straighter edge. Head changes his tune and instead dashes a single wide of mid on.

"Morning Geoff," writes Simon McMahon. "Very much looking forward to this. Final day of the series, two champion teams, result in the balance. Test cricket, eh? Let's play!"

4th over: Australia 14-2 (Head 9, Green 1) A maiden from Jansen to Green, the giants battling one another, and Jansen nearly bowls him, mind you. A short ball that has Green hopping, plays it down into the turf, and it rolls back past his stumps.

3rd over: Australia 14-2 (Head 9, Green 1) Brave of Green to leave the ball outside off. Similar spot to the one that got Marnus, a touch fuller perhaps. He gets moving from the fifth ball, knocks a single into the off side.

2nd over: Australia 13-2 (Head 9, Green 0) Well, I said that Australia needed Head to take a bite out of the chase first, but wasn't anticipating that he would lose two partners in the first over. He decides to do his part anyway. Defends three balls from Jansen, then lets loose as he sees width. Misses his first flail, connects cleanly with his second one along the ground, and connects dirty with his third, in the air through the cordon but safe. Two boundaries, but if I were South Africa, I'd happily feed that shot a few times looking for the mistake.

1st over: Australia 5-2 (Head 1) It had seemed such a quiet start. Travis Head took the first ball, defending crisply with a perfectly vertical bat down the line of off stump. Dolloped away his leg-side run from the second. Then Renshaw gone from the third. He had moved across a long way before glancing, is the main criticism – people always say it's unlucky to be caught down leg, but I'm not sure why. It's a mistimed shot, and moving across does bring the keeper into play, it increases the range of angles off the bat that could be short.

Anyway, then Labuschagne arrived, nicked a ball for four, survived a curling yorker, and tried to leave the length ball.

If you're confused by the score at the top, that's global style, five runs and two wickets.

We said he needed eight, he might take all 10! Marnus Labuschagne is done as a Test cricketer, surely, surely, surely. Not many uglier dismissals than that, as he leaves a ball that jags back and hits his pad. Well outside the line of the stumps, but there's no shot offered, and Dick Kettleborough pops up the finger without demur. Marnus has one last umpire review for old time's sake, and it shows what the live vision suggested: umpire's call on hitting the outside the off-stump. That's good enough to bowl a player, so it should be good enough to trap them as well. Australia struggled to get seam movement yesterday, but with this brand new ball, Rabada does, and irresistibly shapes this match.

Only seven to go, then, Kagiso! One of the blows that Australia could least afford. Renshaw their best long-innings performer, on the evidence of this series. Totally innocuous, ball on leg stump, he's on the move looking to glance as he's done throughout this tour, and he nicks it down the leg-side to the keeper. Out first ball, after Head played a similar glance to get off strike. Labuschagne is into the fire in the first over!

Kagiso Rabada to start us off… if he takes eight wickets today, he'll match Dennis Lillee's 355 Test wickets. Dare to dream.

Send me an email, let's do this with company. Gervase Greene is out of the blocks early.

"I have not looked forward to an evening in front of the telly in a lifetime. (Maybe the last day, the Oval, 2005… There's more sub-plots than an Agatha Christie. Marnus? Trav's spot in the order? Cam Green? Who the hell - and how the hell - we open? The call to send them in…? Wow."

I'm not sure if that means Gervase has never looked forward to an evening in front of the telly, or has never looked forward to one full stop. Either sentiment would be fair.

Now, I bet there is a good chance that you are saying, or that somebody will in your hearing today say, that it's a tough blow for Australia that they don't have Steve Smith playing. Their great batting champion, tough chase without him, et cetera, et cetera.

Not so, King of Siam, because Steve Smith in his long and remarkable career has barely made a run in the fourth innings of a Test, and barely faced a ball on the fifth day. He wins games early, and has never notably won or saved one late. I did the analysis a while back, and it still holds. Interesting to delve into the detail of how a career works.

Long story short, for this job Australia are better off with other players doing it.

What happened yesterday? Great question. A fine day of Test cricket, that's what. But you want to know more. I know a guy who does match reports for The Guardian, let me hook you up.

It would be unfair to say that Australia let a winning position slip on the fourth day of the third Test at Cape Town, only because that would undersell how Ryan Rickelton and Wiaan Mulder prised it away. Australia's vaunted four bowlers, owners of 1,674 wickets at day's beginning, could only raise that to 1,678 by day's end. In the process, a lead of 40 became 287. South Africa had been 40 for four in the first innings at Gqeberha and bounced back to win; they were effectively 40 for four in the third innings here, and now have a great chance to do the same.

I have been saying it every day throughout this match, and most of the days throughout this series, but I can say it with truth one more time: what a beautifully set up contest. The previous 14 days all come down to this. Day five, third Test, Cape Town, where in series terms winner will take all.

Australia must chase 288 to win. South Africa must take 10 wickets. The weather is fine, so the draw is not really on the cards, unless there's a big early collapse followed by a defensive effort. In the main, if this Australian team bats 90 overs, they'll score what needs to be scored in the course of that.

My instinct says South Africa, however. It was not easy to bat out there on day four, which highlights just how well Ryan Rickelton and Wiaan Mulder did so for their twin centuries. Starting was difficult. There was big turn on offer, and SA have a quality spinner as well as their quality quicks. I think 288 looks right this second like a reasonable target but will rapidly look a much taller one with a couple of wickets.

The key, as so often for Australia in recent times, is Travis Head. If he can make a chunky score up front, that might put the others in the frame. If he goes early, which is always a strong chance given his playing style, that might be that.

Another belter of a day awaits. Let's take one more turn through the garden.