After winning the toss and making 189 for nine off their 50 overs, South Africa’s bowlers had a field day on a low, slow turning pitch at Providence Stadium in Georgetown as Australia crumbled to be all out for 142 off 34.2 overs.
Australia made heavy weather of the run-chase right from the start, with the quick departure of dynamic opener David Warner (1), beaten by the pace of Wayne Parnell and trapped leg before.
South Africa were rewarded for playing three specialist spinners but it was 21-year-old Rabada who led the way, using his genuine pace to claim 3 for 13 from seven overs.
He was backed by fellow quick Parnell (2/23), while spinners Imran Tahir (2/39), Aaron Phangiso (2/26) and debutant Tabraiz Shamsi (1/36) collected the other five wickets.
Middle-order batsman Farhaan Behardien top-scored for South Africa with 62 off 82 balls, a man of the match performance, and captain AB de Villiers said his display had given the side momentum.
“I thought we had a fantastic game today,” de Villiers said in an interview.
“That innings that Behardien played got a bit of momentum on our side and then we started (bowling) really well with the two seamers and then the spinners did a fantastic job.”
The only sour note for South Africa was the news Rilee Rossouw incurred a suspected dislocated shoulder when he landed on the boundary rope diving to prevent a four.