The South African cricketers have beaten the West Indies by one wicket and with two balls to spare at Port of Spain to claim a clean sweep in their five-match one-day series.
Shivnarine Chanderpaul's 67 and 53 from Narsingh Deonarine helped the home side to a solid total of 252 for 6.
Hashim Amla (45), Jacques Kallis (57) and JP Duminy (51) provided the impetus for the tourists' response.
A late collapse gave the home side hope of victory but Lonwabo Tsotsobe saw South Africa home in the final over.
The defeat leaves the West Indies with nothing to show for their efforts during this five-game series and is another cruel defeat following their final-ball loss in the fourth one-dayer at Roseau.