The Tunisian side are top of Group B with 12 points from their five matches after a 3-2 win in Rades on Saturday.
Yannick N'Djeng scored twice as Maher Kanzari's men recorded their fourth win of the campaign, but they did not have it all their own way as the Angolan champions fought hard to stay in the game.
Ruben Gouveia cancelled out N'Djeng's opener with a strike early in the second half, only for Oussama Darragi to put the hosts back in front.
Gouveia levelled again soon after but N'Djeng had the final say with an 80th-minute winner.
In Group A, Leopards de Dolisie moved themselves into contention to progress with a 1-0 win over Orlando Pirates.
The result moves the Congolese side level on points with their opponents and Al Ahly with one game to go.
Dimitri Bissiki won the game for Leopards with a 72nd-minute strike that ends the Pirates' hopes of reaching the final four.
