Rhodes cracked 76 off 70 deliveries

But, after Gilchrist and Hayden got the Australians away to a flier with 84 runs on the board in the first 15 overs, the visitors were always in control.

South Africa struggled to get going in their innings and only had 40 on the board after the first 10 overs.

Graham Smith held things together with 46 off 77 deliveries before being controversially given out, caught behind off Shane Warne, after the ball appeared to hit his arm guard.

He was the only batsman to pass 30 before Rhodes and Boucher came together.

When Smith fell in Warne's second over the hosts had stuttered to 110 for three just after the midway point of their innings, but Rhodes and Boucher proceeded to put on 97 in only 13 overs.

Hopes extinguished

Rhodes raced to his third consecutive half-century before finally falling for 76 off just 70 deliveries, while Boucher was unbeaten on 41 at the end as South Africa reached 267 for six.

Any thoughts the hosts had of extending the series into the final two games were quickly extinguished as Gilchrist set about the South African attack.

He survived two early scares, with Herschelle Gibbs missing a run-out chance and Jacques Kallis spilling a head-high slip catch, and the Aussie keeper made sure he took full advantage.

He put on 170 with Matthew Hayden for the first wicket before Hayden was dismissed for 59.

Guided home

When Gilchrist eventually top-edged a hook to debutant Jon Kent off Makhaya Ntini, he had scored 105 off 104 balls and the Aussies were within sight of victory.

Ponting was joined by Damien Martyn and the captain scored an unbeaten 33 to guide them home with eight wickets and eight overs in hand.

The win means Australia take an unbeatable 4-0 lead in the seven-match series, with one match tied and two left to play.