Jacques Kallis and De Villiers shared a century partnership to set up a comfortable 25-run win for South Africa in the third One-Day International against Australia at Newlands on Thursday.
Kallis (70) and De Villiers (80) laid the foundation for a South African total of 289-6, putting on 114 off 131 balls for the third wicket.
Australia made a reasonable start, reaching 66 for one before their innings stalled against the slow bowling of Johan Botha and Roelof van der Merwe.
They slumped to 114 for five and were effectively out of the game with less than 20 overs remaining.
But Callum Ferguson (63) and James Hopes (63 not out) gave their innings respectability with a sixth wicket stand of 97 before Australia finished with 264 for seven.
The win gave South Africa a 2-1 lead in the five-match series, which continues in Port Elizabeth on Monday.
