Al Ahly were beaten 2-0 by Kampala City Council Authority in the shock of the second round of matches so far of the 2018 CAF Champions League.
The eight-time tournament winners were beaten in Uganda thanks to goals from Ibrahim Saddam Juma and Timothy Awanyi.
ES Tunis moved to the top of Group A, meanwhile, with a convincing 4-1 win over Township Rollers in Rades, in which Anice Badri scored twice and set up another.
Holders Wydad Casablanca got their first win of the campaign with a 3-0 victory at home to Togo Port, while TP Mazembe won 2-0 at Difaa El Jadida thanks to two goals in four second-half minutes.
Felix Badenhorst secured a 1-0 win for Mbabane Swallows over Primeiro de Agosto, and ES Setif suffered a 1-0 defeat to Algerian rivals MC Alger thanks to an 89th-minute winner from Amir Karaoui.