Australia will have to defy 139 years of Test history to beat South Africa, who declared at 540-8 shortly after lunch on day four of the first Test at the WACA.
The Proteas resumed at 390-6 on Sunday and increased their lead to 538 runs when skipper Faf du Plessis finally put Australia out of their misery.
Du Plessis' declaration came 3.1 overs after the meal break, when Vernon Philander was clean bowled for 73 by Steve Smith.
Australia will need to set a Test record if they're to win the three-match series opener.
The highest successful run chase in the history of the game came in 2003, when West Indies reached 418-7 to defeat Australia in St John's.
Spearhead Dale Steyn's series-ending shoulder injury means the Proteas will be a bowler down during the final innings of the match, but it didn't hurt them early on, with Shaun Marsh and David Warner both falling within the first 15 overs.
Smith suggested on Saturday that Steyn's absence would embolden the hosts' misfiring batsmen.
But cracks in the pitch and a first-innings collapse of 86-10 will also be on their minds - to say nothing of the demoralising fact Australia have been in the field during every day of the contest.
"I'm a bit stiff and sore," Peter Siddle said after the morning session, calling on his side to show some patience with the bat.
Du Plessis secured a memorable draw at Adelaide Oval in 2012, when the tourists survived four and a half sessions
However, batting time has not been Australia's strong suit in recent years.
Inept batting swung the game the Proteas' way on day two but Australia could easily be chasing a far lower target if they held some catches on days three and four.
Opener Dean Elgar, who scored 127, was on 81 when Mitchell Starc grassed a skied edge on Saturday.
Adam Voges was responsible for the other reprieve handed out on day three, when Quinton de Kock was on one.
De Kock successfully reviewed two dismissals on Sunday morning before Voges held a low catch to dismiss him for for 64.
Philander was dropped on 29 by Josh Hazlewood at fine leg.
"This is sloppy stuff from the Australians ... a lack of awareness from Hazlewood, he's not fully concentrating," Shane Warne said in the Nine Network commentary box.
"Every one of them (catches put down by Starc, Voges and Hazlewood) should have been taken."
HIGHEST SUCCESSFUL RUN CHASES IN TEST CRICKET
418/7 - West Indies beat Australia in St John's in 2003
414/4 - South Africa beat Australia in Perth in 2008
406/4 - India beat West Indies in Port of Spain in 1976
404/3 - Australia beat England in Leeds in 1948
387/4 - India beat England in Chennai in 2008
382/3 - Pakistan beat Sri Lanka in Pallekele in 2015
369/6 - Australia beat Pakistan in Hobart in 1999