Second Test, Melbourne (day one, stumps): Australia 239-8 v South Africa
Australia collapsed dramatically on the first day of the Melbourne Test against South Africa after Ricky Ponting's century had given them the initiative.
If Nel had caught Ponting on 17, Australia would be in dire straits
Ponting fell for 117 to trigger a decline from 207-3 to 239-8 at stumps.
Andre Nel was South Africa's most effective bowler (4-58), with all the wickets coming in a fine late spell.
Shaun Pollock was also in the wickets, finishing with 3-46, but on a two-paced pitch the hosts remain in contention despite a fine day for the tourists.
After removing Ponting, Nel followed up with the wickets of Andrew Symonds, Adam Gilchrist and Shane Warne, all falling for single-figure scores.
And with the first ball of the last over, Makhaya Ntini got a ball to arrow into Brett Lee's pads to compound the Aussies' plight.
It had been Australia's day before the disastrous final session, with Ponting leading the way with Matthew Hayden (65).
The pair shared a stand of 152 after debutant Phil Jacques had gone for two.
The hosts elected to bat after winning the toss in front of a Boxing Day crowd of more than 70,000 expectant fans.
Play got under way half an hour late because of a damp pitch and left-hander Jacques quickly fell - caught at short leg by Jacques Rudolph in Pollock's second over of the day.
However Ponting and Hayden soon seized the initiative, although the captain survived a chance when he was dropped by Nel at square leg off Jacques Kallis when just 17.
Nel made up for his dropped catch with wickets late in the day
Ponting stroked 13 boundaries in his 198-ball innings for his 26th Test century. It has been a phenomenal year for him, with more than 1,500 runs in 2005.
But he was finally dislodged by Nel when the South African quick got a ball to rear up from outside off stump. The Aussie captain, surprised, could only fend it to gully.
Michael Hussey, who ended the day unbeaten on 23, then watched from one end as Nel wrought havoc.
Symonds edged behind for a golden duck, Gilchrist edged to gully and Warne was caught at mid-off slogging.
South Africa's captain Graeme Smith was left to reflect on a good day's work by his men.
He had a good day himself, picking up two sharp slip catches off Pollock's bowling either side of tea to remove Hayden and Brad Hodge (7) .