After two days in Adelaide ruled by batsmen, chiefly Clarke, that other breed of cricketers had their revenge on day three as the conditions turned like a drink driver spotting a booze bus. Australia rolled through the Proteas for 388, a first-innings deficit of 162, but then had their own top order torn apart in quick succession by the most unlikely of culprits, Rory Kleinveldt.

Clarke, the double centurion of the first innings and three other occasions this year, is again charged with averting catastrophe for Australia, in conjunction with his loyal companion Mike Hussey. They survived a dangerous late assault by South Africa's suddenly venomous pace leaders, Dale Steyn and Morne Morkel, and resume on Sunday on nine and five respectively.

Australia, at 5-111, leads by 273 and should still be favoured to complete in the second Test, a result that would inch it closer to a return to the top of the world rankings that could then be secured in Perth. Adelaide's history of terrorising run chases certainly indicates Australia remains well on top despite its Saturday afternoon wobbles.

Only once has a team scored more than 300 in the fourth innings here to win a Test, and that was way back in 1901-02 when Australia managed 315 to beat England. The next best fourth-innings winning total in Adelaide is 239.

There are complicating factors at play, however. Australia will not have the services of its best bowler so far this summer, James Pattinson, in its bid to drive a nail into South Africa's coffin. He left the field with a side strain, then headed to hospital for scans that will probably put a line through him for the third Test as well as the rest of this one.

On the other hand, the Proteas are inhibited significantly by the hamstring injury their most valuable player, Jacques Kallis, is carrying and continuing to bat with despite the pain. Kallis made a gallant 58, batting at No. 9, on Saturday, arresting South Africa's own slide alongside the debutant Faf du Plessis (78).

Where he will bat in the final innings remains to be seen and his situation could turn out alarmingly similar to that of his captain Graeme Smith four years ago when he batted with a broken hand to try and save the Sydney Test.

Australia was cruising at 0-77 after tea when Kleinveldt, hitherto known here for his couch potato build and positive test to marijuana, turned the faces of David Warner (41), Ed Cowan (29) and Rob Quiney (0) green. All three departed in short time, Quiney's edge completing an unfortunate pair that may well signal the end of his brief Test career, with Kleinveldt taking 3-14 in six overs.

When Ricky Ponting then fell, chopping on to Steyn for 16, and nightwatchman Peter Siddle was outsmarted by Morkel cheaply, Australia had lost 5-26 .

The Australians will rely heavily on off-spinner Nathan Lyon to defend their lead, and he offered encouraging signs on Saturday, removing Jacques Rudolph for the third time in this series and then bowling Morkel around his legs.

''I'm excited about the days ahead,'' he said. ''There is definitely going to be a chance to hopefully contribute to a Test match victory for Australia. ''We're pretty happy with where we're sitting at the moment with a 270-run lead.

''It's going to be hard work in the morning but hopefully Pup and Huss can fight the reverse swing and spin and hopefully get a good lead again. [The wicket] is probably going to deteriorate a bit more as the match goes on. Reverse swing and spin are going to play a massive role in it.''

Ben Hilfenhaus finished with the best figures of 3-49 but it was Siddle who took the crucial wickets of Smith and A.B. de Villiers, and Clarke's off-spin that ended Kallis' brave 50.