Tunisia capitalized on brief play from a 10-man Zambian squad after Emmanuel Mayuka went to the sidelines, as Ahmed Akaichi scored and Yasine Chikhaoui followed up to give Tunisia the win.
The win puts Tunisia at the top of Group B with four points after two games, while Zambia has just one point, with one last game to play in order to advance.
Mayuka opened the scoring for Zambia in the 59th minute, but then injured himself in the 67th minute. As play continued with Mayuka on the sidelines, Akaichi pounced on a goal mouth scramble to punch home an equalizer for Tunisia.
Chikhaoui headed home the winning goal for Tunisia at the 89th minute.
Zambia must grab a win against Cape Verde in its last qualifying match, to stay in contention for the knockout round. Zambia has also not won a match since winning the Cup of Nations in 2012.
In other Group B action, the Democratic Republic of Congo and Cape Verde battled to a scoreless draw. Both sides must win their final matches in order to advance.