McGrath breaks World Cup record

The 37-year-old veteran claimed three for 14 in his opening six overs spell to take his tally for the tournament to 25 wickets - the most any bowler has claimed in a single World Cup.

His efforts helped reduce South Africa, currently rated as Australia's nearest challenger, to 27 for five and although Herschelle Gibbs and Justin Kemp forged a 60-run stand they were still struggling on 90 for six at the halfway stage of their innings.

South Africa had decided to bat first in the hope of putting Australia under pressure by setting a competitive target, but very quickly slipped into trouble.

It took the reigning world champions just 15 deliveries to make their first breakthrough with Nathan Bracken dismissing South African captain Graeme Smith.

Attempting to force the pace, Smith advanced down the pitch to try and hit over the top but was beaten by Bracken's outswing and had his off-stump knocked back.

New batsman Jacques Kallis seemed intent on proving a point when he arrived at the crease after Australia had revealed in the build-up they hoped he was in early because they believed he slowed down the South African tempo.

Kallis signalled his intent by hitting McGrath over the top of extra cover for four to get off the mark, but next ball made the same mistake as Smith by advancing down the wicket and Australia's veteran seamer hit his off-stump.

Opener AB de Villiers was fortunate not to follow Kallis in the next over when, despite South Africa being on a perilous 27 for two, he attempted a suicidal single off Bracken.

Pushing straight to Shane Watson at mid-on, de Villiers set off and would have been several yards short had the throw hit the stumps at the non-striker's end. But it was only a temporary reprieve with de Villiers falling two overs later to Shaun Tait's fifth ball when he nervously pushed outside off-stump and edged behind to wicketkeeper Adam Gilchrist.