Australia need six wickets to take a 1-0 lead in the Test series and weaken South Africa’s hold on their No.1 Test ranking.
Strikes by spinner Nathan Lyon and quick Peter Siddle left the Proteas tottering at 4-45 this afternoon before AB de Villiers and debutant Faf du Flessis steadied the innings with nearly two watchful hours together.
The pair will start at 4-77 tomorrow and will have to bat for much of the day if South Africa are to save the second Test.
Showers are forecast but should dissipate by lunch.
The prospect of scoring another 353 to win the match is fanciful, even with the absence of paceman James Pattinson, who has been ruled out for the remainder of the Test summer with a side injury. However, Jacques Kallis is listed to bat next and showed in the first innings that his hamstring injury does not inhibit his hitting power.
But de Villiers (12 off 101 balls) and du Plessis (19 off 74) showed signs of falling into the same trap that snared Jacques Rudolph, who was becalmed for most of his turgid innings.
Neither batsman revealed any interest in turning the strike over or taking the attack back to Australia during a 32-run stand that lasted 29 overs.
Lyon claimed Rudolph for the fourth time in the series when he drew an inside edge to short leg as the left-hander lunged around his flat front foot.
Rudolph got off the mark first ball but then spent the next 33 deliveries adding just one more single before succumbing to the pressure building on him.
Opener Alviro Petersen was bowled by Siddle for 24 that included several of the luscious drives he displayed at the Gabba and in the first innings.
South Africa's bid to score a world record 430 got off to a disastrous start when first innings century-maker Graeme Smith (0) edged Ben Hilfenhause to Ricky Ponting in the opening over.
Lyon then struck another huge blow for the Aussies when he had Hashim Amla (17) caught at slip by Michael Clarke, with the tea score of 2-40 already ominous for the Proteas.
The Australia skipper declared his side's second innings at 8-267, with Pattinson and Hilfenhaus adding an unbroken 47 for the ninth wicket.
Clarke’s departure for 38, trapped LBW by Dale Steyn, ended his remarkable run of double-centuries but he still has 527 runs in the series.
Mike Hussey kept ticking over to add a busy half-century to his 100 and 103 in his other innings in the series.
Hussey (54) holed out to Morne Morkel just before lunch as the hosts went to lunch on 7-206.
South African spinner Imran Tahir finished with the worst bowling figures in Test match history - 0-260 from 37 overs.