Al Ahly missed the chance to move within a point of Zamalek after suffering a 1-0 loss to Ghazl El Mahalla on Monday night.
Amr El-Sulya and Yasser Ibrahim were drafted into Mosimane's line-up after starting on the bench last Friday.
After dropping points over the weekend, the Red Devils managed to carve out a couple openings for Hussein El-Shahat but Amr Shaaban was equal to both efforts in the first 15 minutes.
The home side broke the deadlock in the 35th minute, with Ashrad Mohamed Sayed rattling the back of the net with a powerful effort from distance.
After failing to find a breakthrough in the first half, Mosimane responded with a double change at the start for the second stanza after introducing Walid Soliman and Mahmoud Walid.
Unfortunately for Mosimane's side, the changes failed to make the desired impact as they failed to restore parity in the second half.
The defeat leaves Al Ahly in second spot, four points behind league leaders Zamalek with two games in hand.