Mohamed Sherif, Amr Al-Sulaya and Mohamed Abdelmonem were recalled by Ahly, with South African international Percy Tau amongst the starters yet again.
Ahly raced into the lead with just 12 minutes played as Al-Sulaya drilled home from the penalty spot after the Video Assistant Referee (VAR) penalised Raja for a handling Ayman Ashraf's cross.
The holders extended their advantage towards the half-hour mark as a cutback left of the area from Tau saw an on-rushing Hussein El Shahat take aim and finished easily.
The Green Eagles shook up their stall ten minutes to halftime with Ilias Haddad sacrificed for Fabrice Ngoma, whilst El Shahat had a towering header cleared off the line at the other end.
Raja got a revival in the final seconds to halftime when Mohamed Zrida slammed a low cross onto the near post and into the net.
With Hamdy Fathi introduced for Ahly in place of Dieng, the host edged to a third minutes in through a smart header from Ahmed Abdel Kader but he went wide.
Al Ahly were awarded another penalty towards 60 minutes when Marouane Hadhoudi handled a goal-bound shot from El Shahat and received a red card, but Anas Zniti denied Al-Sulaya this time.
However, the Cairo Red Devils were at the receiving end of more chances a little later with numerous box entries which Tau, Abdel Kader and Al-Sulaya particularly missed.
Raja wasted a golden one-on-one opportunity in the dying seconds through Hamid Ahadad, whilst Zniti produced a point-blank save at the other end as the defending champions take a slim lead into the second leg.