Sydney: Paceman Peter Siddle struck five stunning blows as South Africa dismissed for 327, handing Australia a 118-run lead on day three of the third Test at the SCG.
Later Aussie lead was stretched to 151 as they reached 33 without loss at stumps on third day of the Test.
South Africa had been looking on track at 5-308 to match Australia's total before a dramatic collapse. Boucher shared in a 115-run partnership with Morne Morkel (40) to frustrate the home side before Siddle changed the course of the match with his inspired spell.
Siddle removed Morne Morkel, Paul Harris, Dale Steyn and Mark Boucher in quick succession.
South African captain Graeme Smith was forced to retire hurt on 30 yesterday after breaking his hand and will take no further part in the match.
Gaping cracks often caused havoc for the batsmen but also often worked in their favour with several nicks not carrying to the slips cordon.
The Proteas lost three wickets this morning and then another in the middle session to slump to 5 for 162 before the rearguard from Boucher and Morkel.
South Africa had some unbelievable luck today with two deliveries hitting the stumps but not dislodging the bails.
Morkel chopped a Mitchell Johnson delivery on when he was on 34 while Boucher was beaten all ends up by a Nathan Hauritz delivery when he was on 27.
The ball went straight through Boucher's defences and rapped the base of leg stump, with the bail bouncing up but not falling off.
Johnson was the other star for Australia, first having Jacques Kallis caught by Matthew Hayden at first slip for 37 early in the day.
Kallis departed just 15 runs short of becoming the eighth player in Test history to accumulate 10,000 runs.
Johnson also dismissed Melbourne hero JP Duminy lbw for 13 and spectacularly ran out AB de Villiers for 11.
De Villiers contributed to his own dismissal, failing to back up at the non-striker's end when partner Hashim Amla set off for a quick single.
He also looked over his shoulder instead of sprinting for his ground as Johnson let rip from mid-off.
Debutant all-rounder Andrew McDonald also snared his maiden Test wicket, with Amla adjudged lbw for 13.
Fellow debutant Doug Bollinger was unlucky not to open his account with several nicks not carrying.