Ricky Ponting hit an unbeaten 87 as Australia reached 180-7 at tea on Day Four of the second cricket Test in Melbourne, a lead of 115 runs over South Africa.
Brett Lee was bowled by Jacques Kallis on the stroke of the interval as top-ranked Australia lost four wickets for 94 runs in the afternoon session. Dale Steyn earlier removed Michael Clarke and Andrew Symonds in the same over and Makhaya Ntini dismissed Brad Haddin.
Resuming on four without loss, Australia turned a 61 run deficit into a 21 run lead in the morning session but lost Matthew Hayden, Simon Katich and Michael Hussey in the process.
Steyn accounted for both Australian openers as the home side reached 86 for three at lunch on the fourth day of the second Test against South Africa at the MCG.
Following South Africa's battling rearguard action on Sunday, Ricky Ponting's men were looking to post a healthy second-innings total to give themselves a chance to level the series following the defeat in Perth.
Having moved to 37, Australia were dealt their first setback when Hayden was dismissed for 23 when the burly left-hander drove Steyn straight to Jean-Paul Duminy at short extra cover.
It was a disappointing end with the 37-year-old looking in reasonable touch and needing a big innings to potentially save his Test career.
Katich (15) departed in Steyn's following over when he was caught behind by wicketkeeper Mark Boucher after finding a wide half-volley too tempting to leave alone.
Hussey, out for a duck in the first innings, then completed a miserable Melbourne Test when Morne Morkel got one to lift viciously off a length and it hit the batsmen on the helmet before ballooning to Hashim Amla at midwicket.
The ball was adjudged to have brushed his glove first although replays tended to suggest otherwise and a clearly disappointed Hussey trudged back to the pavilion having made just two.
Ponting (32 not out) and Michael Clarke (9 not out) were the men at the crease at lunch and much will rest on the duo's shoulders if Australia are to have any chance of squaring the series.
