Australia have been comprehensively outclassed by South Africa, losing by 134 runs to move to a 0-2 record at the men's Cricket World Cup.

After having sent the Proteas in to bat nothing went right for the Australians, who were savaged by opening batsman Quinton de Kock (109) as South Africa set a total of 7-311, which was helped by some sloppy Australian fielding.

Australia put down six catches as de Kock smashed a second-straight World Cup century to power South Africa to their total.

Australia could do little in response and the five-time ODI World Cup champions never threatened as they were all-out for 177 in the 41st over.

Openers David Warner and Mitchell Marsh fell cheaply before South African quick Kagiso Rabada took big wickets.

First he trapped Steve Smith LBW, the Australian star stunned to be given out on review, as the ball was shown to be clipping the top of leg stump.

Rabada then clean bowled Josh Inglis for 5, before he got Marcus Stoinis caught behind for the same score.

Stoinis struggled upon his return to the side in the field too, bowling just two overs and putting down an easy catch.

Stoinis is averaging 16.37 from his last 32 ODIs and has failed to pass 50 since March 2019.

A 69-run partnership between Marnus Labuschagne (46) and Mitchell Starc (27) was the only time in the match Australia looked remotely comfortable.

The result leaves Australia staring down the barrel early in the lengthy tournament and they simply have to beat Sri Lanka on Monday at the same venue if they are to arrest their sliding ladder position and net run rate.

ABC/AAP