Australia is almost in the lead from just one session of batting after South Africa was bowled out for 152 on the opening day of the first Test in Brisbane.
David Warner was caught out off the first ball of the innings and was quickly followed to the sheds by in-form Queenslanders Marnus Labuschagne and Usman Khawaja, but Travis Head launched an aggressive counter-attack at the Gabba.
Steve Smith and night watchman Scott Boland fell in the final two overs of a 15-wicket opening day.
Look back at all the action as it happened in our live blog, check out the scorecard, or listen to our live ABC radio coverage.
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Live updates
Thanks for being with us
By Simon Smale
Well, what a day's play.
Thanks for joining us on what has been a superb day of cricket - very much a day for the bowlers.
The match is in the balance and I can't wait to see what happens in the next couple of days.
Myself and Jon Healy will be back here then and we look forward to having you join us.
What goes around comes around?
By Simon Smale
Oh dear! I just hurried back from the bakery only to find the Aussie batsmen are teetering on the edge. It was all fun and games until it happened to OUR batsmen!
- Mike
It's definitely been that sort of pitch, it's offered plenty to the bowlers, seam, bounce and early on a little bit of swing as well.
Batting has been tough, no matter who you are.
Stumps: Australia 5-145 (Head 78)
By Simon Smale
Well, what a day of cricket.
297 runs have been scored. 15 wickets have fallen.
Australia started out by making a serious statement with the ball, but then South Africa hit back with the ball themselves.
Australia are only 7 runs behind with five wickets in hand and, most crucially, Travis Head still there on 78 from 77 balls.
Those two late wickets certainly help boost South Africa's hopes, because if Smith and Head were still there together at the close, things might have been a bit tougher.
But there's only one of that partnership now, but it is Travis Head.
He looked like he's been playing a different game to everyone else so far, but almost everyone else has struggled.
Only two partnerships of note across the one and a half innings, one of 98 between Temba Bavuma and Kyle Verreynne, and one of 117 between Head and Steve Smith.
This match is very much in the balance - but I can't see it going five days.
Out! Boland edges behind!
By Simon Smale
Great bowling from Rabada, who gets his man caught behind by Verreynne.
And that's the final action of the day, stumps have been called, so Boland has, actually, done his job.
34th over - Rabada waits to run in again
By Simon Smale
Boland and Head had a nice little chat in the middle to eek out some more time.
33rd over - In comes the night watchman
By Simon Smale
Scott Boland is coming into the middle as night watchman.
Alex Carey was padded up, but they've opted to try and keep him fresh for the morning.
Four balls to face, lights are on, Nortje is bowling at 145kph. Have fun, Scott.
He backs up and attempts to swish at a bouncer.
148.6kph, the fastest ball of the day, right on the grill, Boland fending it up in the air but safe to short point.
Real pace! 150.5kph and Boland fends the ball just past the man at bat pad for a single! What courage! Brilliant stuff, and the crowd appreciates it too, a huge roar for his first runs.
Head defends the last to end the over.
Bowled him! Smith has to go!
By Simon Smale
Oh what a ball!
That's nipped back and just clipped the off bail - a fantastic ball to get at any time in your innings.
Smith falls for 36 off 68.
33rd over - Nortje comes in again with his express pace
By Simon Smale
Another 144.4 ball from Nortje to open things up.
Travis Head is just not normal
By Simon Smale
What's with the accelerated run rate - is it just Head settling into his natural game?
- Mike
He's been doing this for a while now, admittedly, but he looks like he's playing a completely different game to everyone else.
32nd over - Rabada comes in again
By Simon Smale
BEATEN! Smith is squared up and intimates that the ball moved a bit off the seam.
He takes a single to square leg next ball.
Three slips in place now for Head, a gully and point.
FOUR! Head down the ground, didn't look like he timed it perfectly but still a gorgeous strike and another four to add to his tally, which now stands at 76 off 72.
Rabada with a good response, hitting Head in the midriff.
Head clips to backward square leg for a single.
31st over - Nortje comes in again
By Simon Smale
Wow, he's cranking this pace up, 145.7kph that time.
Now 147.7kph!
148kph!
That's just shy of 92mph in old money.
Smith has not had to play a single one of those though, and when he is made to (144kph, if you're interested) he clips it to wide mid on for a single.
Head is struck on the pads, far too high to be worth a shout, and there's no run.
30th over - Rabada comes in again
By Simon Smale
Bang! 136.1kph right on the money from Rabada, has Head ducking and almost toppling. Just missed the helmet I think - and the lack of support staff running on makes me think it did miss it. Close though, a good bumper.
That's what's so good about Head though for me, straight after that difficult bouncer he's straight on the attack driving straight to wide mid off for no run.
A straight drive is fielded by Rabada and has Smith flinging himself back into his crease at the non-strikers end.
Another bumper, another good one too that has Head ducking and driving.
Four! Edged past second slip! All that good work produces the edge and South Africa can't capitalise.
29th over - Nortje is back
By Simon Smale
The keeper and slips are standing a long way back to Nortje, who is already up at 140kph this spell.
Four! Travis Head is making this look very easy, a lovely cut backward of square for yet another boundary, his 11th four of the innings.
He takes a single down to get off strike.
Nortje just hits 144.4kph again. Rapid stuff but outside off and easily left alone. Now he hits 145.6kph.
28th over - Rabada comes in again
By Simon Smale
There's still some extra bounce out there, as Rabada gets Head on the thigh pad, squaring him up too.
There is still life in it, South Africa just need to work out how to extact it.
Smith pushes away square for two runs,
That's the century partnership
It's been a crucial one too, off 110 balls.
Smith leaves with a swish of his bat and earns a furious stare from Rabada, who's stopped having fun I think...
More bounce from Rabada, Smith has to square himself to defend that.
This extra bounce does make me thing a few bouncers wouldn't go amiss here, just to try and unsettle them. Sure, both play the short ball well, but some snorters could help.
27th over - Ngidi comes in again
By Simon Smale
Smith plays a sumptuous square drive but it's fielded at point, so only two runs instead of the four it probably deserved.
CLOSE! Smith was about half an inch from playing onto his own stumps there. That is so close. What a let off.
Smith glides down the pitch like a ballroom dancer after playing a defensive stroke, complete with a little spin to boot. That's when you know he's in good touch, aside from the plethora of sumptuous shots he's been gracing us with, of course, just the ease of his footwork in those little moments. It's almost baletic.
26th over - Rabada is continuing to roll in
By Simon Smale
Head is playing shots, but picking out the field.
Four! Until then! The fourth ball of the over flying to the boundary off the straight drive. That's his first four down the ground this innings.
Elephant in the room time, is David Warner fighting for his spot?
By Simon Smale
So, David Warner is in a slump.
There is a suggestion that it is terminal for his spot in the Test team.
Can the 36-year-old turn it around? Will he be given time?
I can't see him being dropped ahead of his 100th Test and, to be honest, Australia probably needs his experience in India.
But the Ashes in the winter? That may not go well for him and perhaps a decision may need to be made before then.
