The Proteas won the toss and opted to bat first against the associate team in their World T20 fixture.
The South African side managed 209/5 on the scoreboard as AB de Villiers made 64 runs from 29 balls which include four boundaries and five sixes.
Opener Quinton de Kock and and skipper Faf du Plessis made 45 and 41 runs respectively for the side.
Afghan bowlers Amir Hamza, Dawlat Zadran, Shapoor Zadran and Mohammad nabi dismissed one South African batsmen each.
Afghanistan team, chasing 210 runs to win, were bowled out on 172 runs in 20 overs.
Mohammad Shahzad was the highest scorer for the team as he scored quick 49 runs from 19 balls with three boundaries and five sixes.
Gulbadin Naib made 26 runs from 18 balls while Noor Ali Zadran and Samiullah Shenwari contributed 25 runs each with the bat.
Chris Morris was grabbed four wickets for Proteas while Kagiso Rabada, Kyle Abbott and Imran Tahir grabbed two wickets each.
Faf du Plessis (captain), Kyle Abbott, Hashim Amla, JP Duminy, Quinton de Kock, AB de Villiers, Imran Tahir, Chris Morris, David Miller, Kagiso Rabada, David Wiese
Mohammad Shahzad, Noor Ali Zadran, Asghar Stanikzai (captain), Gulbadin Naib, Mohammad Nabi, Samiullah Shenwari, Najibullah Zadran, Rashid Khan, Amir Hamza, Dawlat Zadran, Shapoor Zadran