Striker Bassem Morsy and playmaker Aymen Hefny scored in the first half as the ‘White Knights’ continued their impressive run in the second tier continental club championship.
With nine points, the Cairo giants are closest to reaching the last four halfway through the group stage.
Earlier, Morsy had broken the deadlock on the second minute connecting home a perfect cross from captain Hazem Emam from the right.
Despite the absence of Ndey, Leopards had some good moments with Niger-import Mahamane Cisse combining effectively Bdimbou and Cesair Gandze upfront. Leading marksman Gandze, failed to take his tally to four goals in the competition with a low shot on 27 minutes from a Bidimbou assist that Shenawy sent out of danger.
Zamalek were dangerous each time they moved up despite the visitors having the better of possession. On 34 minutes, the Egyptians were rewarded with a penalty after Herman Nkodia fouled Emam in the vital area and Hefny made no mistake slotting home from the short distance.
The Congolese resumed stronger and Cisse missed a sitter five minutes into the second half, blasting wide from a Davy Bissiki cross from the left.
Leopards goalie Chancel Massa denied substitute Moustafa Fathi with a diving save off his goal bound shot at the edge of the penalty area in the closing stages.
The Congolese, winners three years ago remain winless at the group stage with just a point from three games.