Mitchell Starc led Australia's recovery as the defending champions fought back with the ball against South Africa on the first day of the World Test Championship final at Lord's on Wednesday.
Australia were dismissed for just 212 after South Africa captain Temba Bavuma won the toss in bowler-friendly conditions, with pace spearhead Kagiso Rabada taking 5-51.
But at stumps, South Africa had slumped to 43-4 in reply, a deficit of 169 runs, as Starc finished the day with figures of 2-10 in seven overs.
South Africa's Marco Jansen, who took 3-49, admitted it had been a mixed day for the Proteas, telling the BBC: "Bowling-wise I think we did well... They bowled well, and we are going to have our work cut out for us tomorrow."
Given the strength of both teams' pace attacks, the key question was always likely to be which side could put enough runs on the scoreboard.
Australia's total certainly looked a lot healthier when left-arm quick Starc had Aiden Markram playing on for a duck before dismissing Ryan Rickelton (16) to leave South Africa floundering at 19-2.
Novice number three, Wiaan Mulder, dropped on one, was bowled by Australia captain Pat Cummins, having taken 44 balls to make six.
And shortly before the close, Josh Hazlewood bowled Tristan Stubbs.
Australia had earlier slumped to 67-4 at lunch.
But star batsman Steve Smith (66) and all-rounder Beau Webster (72) repaired the damage with a fifth-wicket stand of 79.
"Two good bowling outfits, it was tough work for the batters," Webster told the BBC. "We've got a score on the board and to grab four scalps at the end of the day, I think we're pretty happy."
Webster, however, would have been lbw to Rabada for eight if South Africa had reviewed an original not-out decision.
"There were a couple of reviews throughout the day which could've gone either way," said Webster. "The degree of seam movement up the slope was tricky."
Rampant Rabada
Australia were in desperate trouble in the early overs, reduced to 16-2 after losing Usman Khawaja and Cameron Green in a single Rabada over.
The 30-year-old, who has more than 300 Test wickets, is playing his first Test after serving a one-month ban for cocaine use earlier this year.
"It means a lot to me playing for South Africa, I give my all every time. I am so happy to do the job out there," Rabada told Sky Sports.
Australia have struggled to find an opening partner for Khawaja since David Warner's retirement 17 months ago, with Marnus Labuschagne the latest batsman tried out.
The 30-year-old, without a Test century for nearly two years, battled hard for 17 off 56 balls before falling to towering left-armer Jansen.
Australia had been in similar trouble in the 2023 final against India across London at The Oval, only for Smith and Travis Head to both score hundreds as they turned the match in their favour.
Head, however, could only manage 11 before he glanced at Jansen, with Kyle Verreynne holding an excellent diving one-handed catch.
Smith went to fifty before falling to part-time spinner Markram after Jansen, at slip, clung on at the third attempt.
Australia lost their last five wickets for just 20 runs, with Rabada ending the innings when he bowled Starc.
Rabada's haul meant he surpassed Allan Donald's tally of 330 Test wickets in his 71st match compared to the retired South Africa great's 72 Tests.
"That's awesome," said Rabada. "Allan Donald, what a legend, it means a lot to get past someone like him."
Australia have struggled to find a regular opening partner for Khawaja since David Warner's retirement 17 months ago, with Labuschagne the latest batsman tried out.
The 30-year-old, without a Test century for nearly two years, battled hard for 56 balls.
But on 17 he was undone by a classic piece of fast bowling from towering left-armer Jansen.
Hit on the shoulder the previous ball when trying to duck a bouncer, Labuschagne pushed tentatively at a Jansen delivery from around the wicket and got a faint edge through to wicketkeeper Kyle Verreynne, leaving Australia 46-3.
They had been in similar trouble in the 2023 final against India across London at the Oval, only for Smith and Head to both score hundreds as they turned the match in Australia's favour.
Head, however, could only manage 11 on Wednesday before he glanced Jansen, with Verreynne capping an excellent fielding display by South Africa as he held an excellent diving one-handed catch.
South Africa are aiming to win their first major trophy since lifting the ICC Knockout, a forerunner of the Champions Trophy, in 1998.
The top-ranked Australians, who beat India in the 2023 WTC final, have won multiple white-ball trophies.
Teams
Australia: Usman Khawaja, Marnus Labuschagne, Cameron Green, Steve Smith, Travis Head, Beau Webster, Alex Carey (wkt), Pat Cummins (capt), Mitchell Starc, Nathan Lyon, Josh Hazlewood
South Africa: Aiden Markram, Ryan Rickelton, Wiaan Mulder, Temba Bavuma (capt), Tristan Stubbs, David Bedingham, Kyle Verreynne (wkt), Marco Jansen, Keshav Maharaj, Kagiso Rabada, Lungi Ngidi
Umpires: Chris Gaffaney (NZL), Richard Illingworth (ENG)
TV Umpire: Richard Kettleborough (ENG)
Match Referee: Javagal Srinath (IND)