Second Test, Melbourne, day four (close):
Australia 394 & 247 v South Africa 459 & 30-0
Steyn has taken 10 wickets in the Test
South Africa look poised to seal a historic Test series victory in Australia after bowling out the hosts for 247 on day four in Melbourne.
It left Graeme Smith's side needing just 183 to clinch a remarkable win and at the close they were 30 without loss.
Australia were left staring at a first home series defeat in 16 years after pace bowler Dale Steyn took 5-67.
Ricky Ponting was dismissed one run short of his second century of the game when he was the eighth wicket to fall.
Ponting looked set to become the first man to score a century in each innings of a Test on four occasions.
But his departure all but ended Australia's hopes of posting a difficult total for South Africa, who won the first Test in Perth by six wickets after chasing down a target of 414.
The Australia captain again carried his team's hopes virtually single-handedly after his leading batsmen failed when the world champions resumed on 4-0, 61 runs behind.
Hayden had smashed two fours in three balls off Steyn, but in the same over he drove straight to the man recently positioned at short extra-cover.
Steyn struck again in his next over, Simon Katich chasing a wide one and feathering a thin edge through to Mark Boucher, who took a neat low catch.
Mike Hussey's dismal run of form continued, but his luck was rather summed up by an unfortunate decision from umpire Aleem Dar.
A brutal lifting delivery from Morne Morkel appeared to fly off his helmet rather than bat or glove but the left-hander was given out and has now scored only 10 runs in four innings in the series.
Ponting began to score freely after lunch, with some stylish, trademark drives, but a 96-run partnership with Michael Clarke was brought to an end by Steyn.
A short, wide delivery should have been dispatched to the boundary, but Clarke failed to connect properly and was well caught at short cover.
Steyn made it a double wicket maiden when Andrew Symonds, having seen one edge fall short of Jacques Kallis at second slip, prodded hesitantly at the final ball of the over and was smartly taken by the all-rounder diving forward.
That left the Australians only 80 ahead with five wickets left, but Brad Haddin maintained attacking intentions, skipping down the pitch to hit slow left-armer Paul Harris over mid-off for six.
He made only 10, however, before he was drawn into a drive outside the off-stump by Makhaya Ntini, and the edge was safely pouched by Kallis again at second slip.
In the final over before tea, Kallis collected his 250th Test wicket when Brett Lee, incapacitated by a foot injury but not batting with a runner, got an inside edge on to middle stump.
Ponting found a useful ally in Mitchell Johnson and, despite being in the 90s for over 40 minutes, looked certain to complete his 38th Test century.
But on 99, Graeme Smith left only one slip in place, moved himself to short cover and gratefully took the catch as, for once, Ponting drove loosely.
His team were only 147 ahead, and though Johnson added some useful runs, Steyn returned to dismiss last man Peter Siddle, which signalled his 150th wicket in just his 29th Test and his third 10-wicket match haul.
Lee was given the new ball despite his injury, but Smith outlined his intentions by driving the first ball of the innings down the ground for four.
We've all got to dig as deep as we can to dislodge a few of their batsmen and get a few nerves through their changing room
Smith hit two more fours in Siddle's opening over, but in the next one from Lee, Neil McKenzie was bowled, only for umpire Billy Doctrove to rule that the paceman had over-stepped.
There was no breakthrough in the remaining overs and South Africa stand on the verge of becoming the first team to win a Test series in Australia since Richie Richardson's West Indies in 1992-93.
Ponting admitted his side were up against it, but remained optimistic that they could still snatch victory from the jaws of defeat.
"Whenever we've got wickets against them we've got them in pretty quick succession," he said.
"We have to make sure we just execute perfectly which is one area we probably haven't done as well as the South Africans in the first two games.
"That's the only option we've got. We've got to get out there and give it our best shot for as long as it takes tomorrow and hopefully hand us some chances and have some luck and we'll see what happens.
"We've all got to dig as deep as we can to dislodge a few of their batsmen and get a few nerves through their changing room."
The captain was confident he would be able to call on his premier fast bowler Lee, who is suffering from a serious foot injury.
"It has flared up really quickly and we hope it will plateau now a little bit, just enough to give us the chance to get a few more overs out of him."
The world's three leading news agencies are not covering the series due to a dispute with Cricket Australia.
Reuters, Agence France-Presse and Associated Press have suspended all coverage of the 2008-09 season.
Their photographers and reporters did not supply material from within the ground. As a result, we cannot use pictures from the current match.