Marco Jansen landed Australia in soup with a five-wicket haul that accelerated their collapse on Day 4 after Temba Bavuma, and Jansen himself, tailored South Africa's steely comeback on the previous day. It took just 38.3 overs for Australia to fold for 99 in reply to South Africa's 428/9 declared, and having to bat again with the threat of a big defeat looming over them. Marnus Labuschagne and Travis Head pushed back with a show of defiance but South Africa managed to crack that too, leaving the visitors at 156/4 at stumps.

The morning session belonged to Jansen. He started with a wicket first ball, taking out Scott Boland and then removed Head too. Labuschagne tried to stick around but Simon Harmer took a one-handed screamer diving to his left at gully to dismiss him. Steve Smith and Matt Renshaw dug in for the next 15-odd overs and seemed set to take Australia to Lunch without further damage but Jansen delivered a double-wicket over where he dismissed Renshaw and Alex Carey.

The unravelling in the second session was quick. Beau Webster slashed at a delivery outside the off-stump to become Jansen's fifth wicket of the innings while Wiaan Mulder ended Smith's vigil a couple of overs later. He also closed out the innings with the wicket of Pat Cummins that saw Australia fold one short of a hundred. Expectedly, Bavuma enforced follow-on and Rabada straight away removed Nic Maddinson in the third over.

There was no repeat of the collapse though. Labuschagne and Head joined forces to push back. They batted together for nearly 30 overs, adding 92 together. Labuschagne even escaped a narrow LBW call and thanked the heavens as a review ruled against the bowling side. But he followed that up with the questionable decision of giving Harmer the charge and miscuing a big shot. Jansen, who could do no wrong in this fixture, covered a lot of real estate running backwards and completed a catch to put the brakes on Australia's resilience.

Renshaw tried to kickstart another gritty alliance with Head but Rabada cleaned him up with a ball from round the stumps to which the batter offered judgement. Head ticked along at the other end at a refreshingly fair clip, given the trenches Australia were in, but his batting partners could neither keep up or stay put. Beau Webster was next to trudge back after being trapped leg before by Harmer.

Boland wouldn't have imagined starting and ending the day in the middle with a bat in hand, but that's how it panned out for his team as the Test swung fiercely in South Africa's direction. Head scored a fifty, had a subdued acknowledgement of it, and walked off at stumps on 87* off 138. He has a bigger role to play on Day 5 where Australia will begin 170 runs in arrears, and South Africa, with their focus trained on bowling six good deliveries for series parity.

Brief scores: South Africa 425/9 decl. (Temba Bavuma 179, Marco Jansen 85, Simon Harmer 82; Scott Boland 5-81, Mitchell Starc 3-89) lead Australia 99 & 156/4 (Travis Head 87*; Kagiso Rabada 2-30, Simon Harmer 2-47) by 170 runs.