West Indies collapse from a position of strength as South Africa take series 3-2.
Kieron Pollard registered his sixth T20I fifty; Quinton de Kock 60 in vain as West Indies level series.
Earlier, McCoy and Bravo picked up seven wickets between them while De Kock scored a 51-ball 72
South Africa level series as George Linde, Tabraiz Shamsi squeeze West Indies.
Evin Lewis made 71, including a half-century from 22 balls, to steer the West Indies to an eight-wicket win over South Africa on Saturday.
Left-arm spinner takes 5 for 36 to dismiss WI for 165 in their chase of 324.
Rassie van der Dussen and Rabada rescued South Africa from 73 for 7 by adding 70 for the eighth wicket. Roach picked up four wickets for West Indies
Wiaan Mulder picked up 3 for 1, and Keshav Maharaj, Kagiso Rabada and Lungi Ngidi took two each to give South Africa a lead of 149.
Dean Elgar led from the front with a stoical 77 runs to see his side to 218 for five wickets at stump on first day.
South Africa are in firm control of the first Test against the West Indies after a brilliant century from Quinton de Kock.