Tunisia made the most of Zambia’s wastefulness in front of goal as they came from behind to win.
Emmanuel Mayuka opened the scoring when he blasted home a cross from the impressive Rainford Kalaba.
But Mayuka was injured when stretching for a chance to turn the ball into an empty net and moment’s later Tunisia scored against 10 men when Ahmed Akaichi scored from two yards out.
Tunisia improved after that and Yasine Chikhaoui headed home a late winner.
The Eagles of Carthage are now on four points after two games, with Zambia on one point with one game left in Group B of the Africa Cup of Nations.