South Africa captain Graeme Smith backed his bowlers to promptly dismiss Australia for a second time after his team ambled to its declaration during the opening session of day four in Port Elizabeth.
Smith's declaration when his team was 5-270, giving it a lead of 447, came so late that the Proteas only had 33 minutes to bowl at Australia to end the session.
At lunch on day four Australia was 0-31 after eight overs, needing another 417 runs for what would be a record chase, with Chris Rogers on 21 and David Warner on 10.
Only four teams have scored more than 400 to win a Test: the West Indies' 7-418 against Australia in 2002-03, South Africa's 4-414 against Australia in 2008-09, India's 4-406 against the West Indies in 1975-76 and Australia's 3-404 against England in 1948.
South Africa's task was made harder by three factors: a match-ending groin injury to left-arm paceman Wayne Parnell, the absence of a specialist spinner, and a forecast that there was an 80 per cent likelihood of rain on the final day.
The only thing notable about the Proteas' 17 overs with the bat to start day four was that it included Hashim Amla reaching his 21st Test century, with its scoring rate of 4.59 runs per over only barely ahead of what Australia managed when it began its first innings on day two.
Amla finished unbeaten on 127, although on the final day he produced a subdued 31 from 50 balls, with his initial partner Quinton de Kock streakily scoring 25 off 34. The only batsman who showed the intent and capacity for a late scoring flurry was J.P. Duminy, who was 18 not out off 18 when Smith called him and Amla back to the dressing rooms.
Australia captain Michael Clarke said after day three he would have already declared so as to have had time for five overs at the end of day three, given the weather forecast. He then rebuked a local journalist who questioned his sincerity.
Australia's openers were largely untroubled in the eight-over stint they survived before lunch. The closest South Africa got to breaking through was when Vernon Philander drew an edge from Warner that fell just short of wicketkeeper A.B. de Villiers, partly because the left-hander had cleverly played the defensive shot with soft hands. Rogers enjoyed what was clearly his best start for the series, scoring three early boundaries.
The visitors' day started badly when debutant De Kock was dropped by Steve Smith off Ryan Harris from the second ball of the day. It was one of three particularly nervous moments the 20-year-old survived in the first eight balls he faced on the day, with an edge falling short of slips and a mistimed pull shot that fell safely in the infield. The left-hander eventually fell for 34, to a sharp catch by Clarke at first slip off Nathan Lyon.
South Africa (1st innings) 423
Australia (1st innings) 246
South Africa (2nd Innings - overnight 4-192)
G SMITH b Johnson 14
D ELGAR c Haddin b Siddle 16
H AMLA not out 127
F DU PLESSIS c Haddin b Siddle 24
AB de VILLIERS c Haddin b Johnson 29
Q DE KOCK c Clarke b Lyon 34
J DUMINY not out 18
Sundries (2b, 6lb) 8
Total (5 wkts - decl) 270
Fall of wickets: 20 (Smith), 42 (Elgar), 112 (du Plessis), 167 (de Villiers), 231 (de Kock)
Bowling: M Johnson 15-1-51-2, R Harris 13-1-74-0, N Lyon 17-2-48-1, P Siddle 19-2-89-2
Australia (2nd Innings)
C ROGERS not out 21
D WARNER not out 10
Total (no loss - lunch) 31
Bowling: D Steyn 3-0-18-0, V Philander 3-0-9-0, M Morkel 2-0-4-0.