Clinching the No 1 ranking and a series-winning send-off for Ricky Ponting appears little more than a distant dream for Australia after South Africa breathed fire on day two of the third Test.
With everything on the line, Australia collapsed meekly with the bat and floundered badly with the ball on a disastrous day in Perth.
It was a swift and humiliating turnaround in the match, given Australia had bowled their opponents out for just 225 in the first innings on day one.
South Africa were 2-230 at stumps from 38 overs, with a commanding 292-run lead and Hashim Amla (99 off 84 balls) and Jacques Kallis (17) unbeaten at the crease.
Spearhead Dale Steyn (4-40) starred with the ball before Graeme Smith and Amla took the match from Australia with a thundering 178-run partnership from 153 balls.
Smith (84 from 100) and Amla scored at nearly seven an over and at one point were on track to post the best run-rate ever recorded in a century-partnership. It was the third-fastest 150-partnership of all time.
The veteran pair smashed Mitchell Johnson (1-35), Mitchell Starc (1-76), Shane Watson (0-17), John Hastings (0-47) and Nathan Lyon (0-38) to every corner of the WACA.
Smith was eventually sent packing by Starc after an extraordinary full-stretch diving catch from Lyon in the deep - but Lyon dropped his head shortly after in another Starc over when he put down Kallis.
The day was meant to be about retiring great Ponting rising from the canvas.
Instead, South Africa went to another level and ensured Australia must produce a special performance if they're to push the Proteas off top spot in the Test standings and give Ponting a fairytale.
The record for the highest fourth-innings chase at the WACA was ironically the Proteas hunting down 4-414 to beat Australia in 2008.
Australia's new-look bowling attack were praised for their efforts in dismissing South Africa for 225 on day one.
But in the second dig, they lacked any penetration and looked lethargic.
The quicks were severely punished, and the aggression of James Pattinson and Peter Siddle was sorely missed.
Smith and Amla stuck the boot in with the bat, but earlier Steyn and Vernon Philander (2-55) were the instigators - exploding out of the blocks to have Australia reeling at 6-45 just six overs into the day.
Wicketkeeper Matt Wade (68) resisted with an entertaining display, but Australia were bowled out before tea for their lowest total since their 136 against New Zealand in Hobart last December.
David Warner (13) and nightwatchman Nathan Lyon (7) were gone in the blink of an eye, edging behind in Steyn's first over of the day.
Ponting brought the crowd to their feet when he walked to the middle but lasted just 17 minutes and seven balls before being trapped lbw to Philander.
Michael Clarke's untouchable form hit its first hurdle when he copped the ball of the series from a sizzling Steyn.
Mike Hussey (12) fell cheaply to the unplayable Morne Morkel (1-19).
Not to be outdone in the classic catches department, Alviro Petersen took a beauty on the rope off Robin Petersen (3-44) to get rid of John Hastings (32), and for Australia, Johnson produced one of the great caught-and-bowled efforts to dismiss opener Alviro Petersen (23).
Scoreboard at lunch on the second day of the third Test between Australia and South Africa at WACA Ground:
First innings 225
A PETERSEN c & b Johnson 23 32 20 4 0
G SMITH c Lyon b Starc 84 151 100 13 0
H AMLA not out 99 144 84 10 0
J KALLIS not out 17 25 24 3 0
Extras (4b 2lb 1w) 7
Total (for two wickets) 230
Fall: 28 (Petersen), 206 (Smith).
Bowling: M Starc 10-0-76-1, S Watson 5-2-17-0, M Johnson 7-0-35-1, J Hastings 8-0-47-0, N Lyon 7-1-38-0, M Hussey 1-0-11-0 (1w).
D WARNER c de Villiers b Steyn 13
E COWAN c Kallis b Steyn 0
S WATSON lbw Philander 10
N LYON c du Plessis b Steyn 7
R PONTING lbw Philander 4
M CLARKE c de Villiers b Steyn 5
M HUSSEY c Smith b Morkel 12
M WADE b Peterson 68
J HASTINGS c Petersen b Peterson 32
M JOHNSON b Peterson 7
M STARC not out 0
Extras (5lb) 5
Total (all out) 163
Fall: 3 (Cowan), 18 (Watson), 34 (Warner), 35 (Lyon), 43 (Ponting), 45 (Clarke), 100 (Hussey), 140 (Wade), 162 (Johnson), 163 (Hastings)
Bowling: D Steyn 16-4-40-4, V Philander 16-0-55-2, M Morkel 13-6-19-1, R Peterson 8.1-1-33-3.
Who's the best test cricket captain?