One-day international, Cape Town: South Africa 289-7 (50 overs) beat Australia 93 (34.3 overs) by 196 runs
Ntini's new-ball burst claimed four wickets for just four runs
Fast bowler Makhaya Ntini took six wickets as South Africa crushed Australia by 196 runs to take a 2-0 lead in the one-day series on Friday.
Ntini ended with career-best one-day figures of 6-22 as the tourists were bowled out for 93, their lowest ever total against South Africa.
Earlier, Herschelle Gibbs made 66 and Justin Kemp 51 not out as South Africa reached 289-7 in their 50 overs.
The next game in the five-match series is in Port Elizabeth on Sunday.
Ntini claimed the first four wickets to leave Australia reeling at 7-4 at Newlands.
And two late scalps helped him finish with the best figures by a South African in one-day internationals, beating Alan Donald's 6-23 against Kenya in the 1996-97 season.
Australia's paltry total was 32 runs short of their previous lowest score against South Africa - 125 in Melbourne in 1997/98.
Ntini began his first over by teasing an edge from Adam Gilchrist after Australia's stand-in captain had scored his 8,000 one-day run.
The paceman struck again in the same over when Phil Jaques edged to Justin Kemp at second slip.
And when Damien Martyn mistimed a hook to be caught for four at the fine-leg boundary, Ntini had his 200th ODI wicket.
He then had Michael Clarke caught behind before dismissing Australia's top scorer Shane Watson for 27.
Andre Nel offered good support to Ntini, chipping in with figures of 3-30.
In South Africa's innings, Kemp hit four sixes in his 41-ball innings of 51 while Shaun Pollock struck 38 off 27 balls to take South Africa to 289-7.
Number three Gibbs top-scored in his fourth-wicket stand of 80 with wicketkeeper Mark Boucher (42).
Watson was Australia's most successful bowler, claiming two wickets for 46 runs from his 10 overs.
South Africa: G Smith (capt), B Dippenaar, H Gibbs, A de Villiers, M Boucher (wkt), J Kemp, S Pollock, A Hall, R Peterson, A Nel, M Ntini.
Australia: A Gilchrist (capt/wkt), S Katich, P Jaques, D Martyn, M Clarke, M Hussey, S Watson, B Hogg, B Lee, N Bracken, S Clark.