South Africa settled nicely in the opening 30 minutes of the game and they turned their dominance into goals just before the half-hour mark when Lebo Mothiba fired them ahead.
Keagan Dolly, Lebogang Phiri and Menzi Masuku developed a great understanding in the first half, and looked dangerous in the final third.
Tunisia turned the ball into the own net just before the half-time to sum up what was a very tough first 45 minutes for them.
However, Tunisia kept their SA opponents at bay in the closing stages of the first half, as Dag Gama's side looked to put the game to bed.
Mothiba completed his brace to make it 3-0 in the 63rd minute.
Zaid Patel sealed the victory with a well-taken goal for Amaglug-glug's fourth of the night.
This is how South Africa U23 lined up against Tunisia U23: Goss, Rikhotso, Dube, Mngonyama, Farmer, Motupa, Phiri, Dolly, Masuku, Ntshangase and Mothiba.