Australia stretched their lead to 368 runs on Sunday as South Africa faced a run chase of historic proportions to win the second Adelaide Test.
The home side added a further 95 runs to their overnight 111 for five to tighten their grip on the Test match, with three wickets still intact and five sessions to play under clear skies.
At lunch on the fourth day, the Australians were 206-7 with wicketkeeper Matthew Wade on 13 and injured fast bowler James Pattinson yet to score.
The odds are firmly stacked against the world number one South Africans, needing to set a new record for a successful fourth innings run chase at the Adelaide Oval.
The existing record is the 315-6 Australia scored in 1902 to overhaul England.
Australia's Mike Hussey (L) bats against South Africa on the fourth day of the second Test on November 25. Australia stretched their lead to 368 runs as South Africa faced a run chase of historic proportions to win the second Test.
Mike Hussey, chasing his third successive century in the series, was out in the over before lunch for 54 off 95 balls. It was his 29th Test half-century.
Hussey attempted to pull Morne Morkel but the ball came off high on his bat and he spooned a catch to Dale Steyn at midwicket.
The Proteas' other success in the morning session was the dismissal of Australia skipper Michael Clarke, who scored 230 in the first innings.
Clarke added a further 62 runs with Hussey in the first hour before the Australia skipper fell leg before wicket to Steyn for 38.
Clarke, who was on the back foot and struck on the knee roll, went for a review but the TV umpire confirmed the original decision.