A dropped catch from Usman Khawaja has helped South Africa hammer home their advantage in the third Test, with Australia already trailing by 121 runs at lunch on day three in Cape Town.
The Proteas were 1-65 during Saturday's meal break at Newlands, where Steve Smith's hopes of grabbing a 2-1 series lead were fading fast as dark clouds rolled in over Table Mountain.
Khawaja put down a one-handed diving catch at gully during the first over, at which point both Aiden Markram and South Africa had yet to score.
It was a sharp chance but Mitchell Starc's look of anguish said plenty about its importance.
Markram was 36 not out at lunch, seeking to make the tourists pay in much the same way Dean Elgar did earlier in the match.
Elgar, dropped on 53 by Nathan Lyon during his first innings, carried his bat and finished 141 not out.
Pat Cummins produced another lion-hearted spell on Saturday, having rocked the hosts while snaring 4-7 from 38 balls on day one, but could only conjure one wicket.
Cummins sent down seven overs straight on day three. He got the better of both Markram and Hashim Amla on several occasions but the various edges fell safe.
Elgar attempted to drive a wide ball from Cummins but instead edged it straight to Smith, handing him a sixth catch for the match.
South Africa earlier seized a first-innings lead of 56 runs.
Australia resumed at 9-245 on Saturday, with Tim Paine seeking to extend a fightback that he started with Lyon when their side were 8-175.
Instead the tourists' resistance lasted 2.5 overs, with Kagiso Rabada bowling Australia out for 255 when he had Josh Hazlewood out edging for 10.
Paine finished 34 not out.
"Tim played really well. Tim's probably been our stand-out batsman of the tour," Australia coach Darren Lehmann said.
"He's played reverse-swing well."
