Zamalek needed a second-half goal from Abdallah Sayed to claim a narrow 1-0 win over Masry in Alexandria and reach the Egypt Cup semi-final on Saturday.
Zamalek survived a couple of scares in the first half of the quarter-final game but the versatile Abdallah, who was deployed as a left-back, settled the tie in their favour with a superb strike on 59 minutes.
Abdallah, who is originally a winger, was key player in Zamalek’s triumphant Egyptian Premier League campaign but his strike against Masry marked his first goal with the club.
The Cairo giants will face either Pyramids or NBE Club, who meet on Sunday, in the semi-final as they eye a second straight domestic double.
Both sides wasted two chances apiece in an evenly-balanced first half as Masry, who are managed by former Egypt coach Ehab Galal, made a bold start against their illustrious opponents.
Ex-Zamalek striker Marwan Hamdi forced a superb save from keeper Mohamed Awad, who dived to his right to block a fine angled effort from the towering frontman after five minutes.
Masry’s best chance fell to wing-back Karim El-Eraki, who was picked out unmarked by a floated ball on the stroke of halftime but his dinked effort struck the bar.
In between, Zamalek had a goal controversially disallowed for offside while Emam Ashour could only play the ball across the six-yard box with only the keeper to beat after breaking clear.
Sayed made the difference 14 minutes into the second half when he controlled an inviting cross from in-form winger Ahmed Zizo at the far post, cut inside his challenger and arrowed a delightful shot into the far corner.
Masry pushed forward in a bid to equalise but could only create some half-chances as Zamalek held on to continue their bid towards a 29th Egypt Cup triumph.