Heavy, persistent rain left a large damp area on the pitch which prevented any further play with South Africa at eight without loss after one over in the match at the Kensington Oval on Sunday.
Both teams took two points from the contest. South Africa remain top of the standings on 12 points followed by the Australians on 11. Hosts the West Indies, on eight points from four matches, face Australia on Tuesday at the same venue.
West Indies play South Africa in the last preliminary match on Friday.
The final, matching the top two teams from the round-robin phase, is set for June 26 at the same venue.