Australia had South Africa right where they wanted them, but Hashim Amla and AB de Villiers have seized control of the second Test in Johannesburg with a magnificent unbeaten 139-run stand.
The Proteas are 3-229 and lead by 199 runs after day three of a match Australia must win to square the series.
When Amla (89 not out) and de Villiers (70 not out) came together before lunch, South Africa were reeling at 3-90 - just a 60-run advantage over Australia's first innings total of 296.
However, the experienced pair have dug in their heels for more than 41 overs, and Australia are in grave danger of being batted out of the match.
Bad light ensured a premature call for stumps in front of a big crowd on Saturday, which honoured the passing of South African-born England Test player Basil D'Oliveira, aged 80, and wore pink for the McGrath breast cancer foundation.
History is steeply against Australia, only four teams have ever won in Johannseburg batting last.
The record fourth innings run chase at The Wanderers ground is 294 set by Australia in 2006 and unless the tourists can roll South Africa quickly on day four, their struggling top order are facing a record pursuit on a fourth and fifth day pitch.
Debutant fast bowler Pat Cummins had put Australia in a strong position with two wickets in the first session of day three, but despite a few close calls, South Africa didn't crack again.
Cummins (2-46) was by far the standout, with his more experienced fast bowling partners Mitchell Johnson (0-77) and Peter Siddle (0-41) struggling for confidence and inspiration.
Before the day started to get away from Australia, 18-year-old Cummins announced himself as a Test star and the future leader of the attack with a brilliant performance in the opening session.
Under-pressure fast bowler Johnson drastically shortened his run-up, determined to try anything in a bid to return to form and stay in the team.
The desperation measure didn't work and Johnson remained wicketless.
Cummins and five-game rookie spinner Nathan Lyon (1-41) stepped up, but Johnson continues to see his Test future flash before his eyes.
Proteas openers Jacques Rudolph (24) and Graeme Smith (36) had comfortably progressed to 40 without loss before a Cummins bouncer caused Rudolph to miss-time his hook and pop one straight up for Brad Haddin to take with the gloves.
Smith and Amla got going for a while as well but persistent bowling from Lyon eventually cracked the South African skipper and Smith carelessly guided one to Phil Hughes at backward point to make the score 2-75.
Cummins was at his best in the 28th over when he worked out danger man Jacques Kallis (2) with a ball that did just enough and got an edge to Michael Clarke at second slip.
- AAP