Batting first, South Africa Under-19 team made 187 in 48.3 overs.
In reply, India dished out a solid batting display to scoring 190 for 1 in 42.3 overs on Thursday night.
With this win India have taken 1-0 lead in the 3-match series. For India U-19 team, openers Divyaansh Saxena (86 not out) and N Tilak Varma (59) shared a 127-run stand to take the game away from South Africa.
Ravi Bishnoi scalped three wickets, while Kartik Tyagi, Shubhang Hegde and Atharva Ankolekar picked up two wickets each.
India and South Africa will meet again in the second match of the series on Saturday.