A second-half goal from winger Ibrahim Hassan lifted Zamalek to the CAF Confederation Cup semi-final with a nervy 1-0 victory over Morocco's Hassania Agadir in Suez on Sunday.
Hassan's smartly-taken volley from a tight angle four minutes into the second half separated both sides after the first leg ended in a 0-0 draw.
The second period was action-packed and controversial, with the referee disallowing what looked like legitimate goals for both sides.
Zamalek will face the winner of the remaining quarter-final clash between Tunisia's Etoile Sahel and Sudan's Hilal.
The hosts received an early blow when midfield linchpin Ferjani Sassi, the team's primary source of creativity, was stretchered off after appearing to sprain his ankle.
He had just returned from suspension, with Zamalek struggling without him in the past two games.
Zamalek still dominated possession but were let down by some poor touches in the final third. They also found it hard to move the ball around smoothly, given Agadir's compact display.
The hosts were given a let-off when Mahmoud Alaa escaped what looked a certain red card when the already-booked central defender tugged a forward on the edge of the area.
Zamalek's only chances fell to playmaker Mohamed Ibrahim, who replaced the injured Sassi.
He was found unmarked by a low cross from Mahmoud Kahraba but his mis-hit effort went wide. He could have made amends on the stroke of halftime though but his low shot on the turn narrowly missed the target from inside the area.
Hassan sent the home fans into raptures in the 49th minute when he made the most of a poor defensive clearance that fell to him, with his left-foot volley pushed by the keeper into the net at the near post.
Agadir abandoned their cautious approach and poured forward in search of a vital goal which would have taken them to the last four on the away-goal rule.
They were unlucky on two occasions, with Karim El Berkaoui curling a delightful shot just over the crossbar and Imad Kimaoui having a volley denied by the woodwork, with El Berkaoui blasting the rebound high over with the goal at his mercy.
Agadir were harshly denied an equaliser four minutes from time when a close-range effort following a goal-mouth scramble appeared to have crossed the goal-line before keeper Mahmoud Gennesh blocked it with his legs.
At the other end, Hassan scored again after finishing off a breakaway but his goal was chalked off for handball, although television replays showed that the ball had struck his chest.
Zamalek breathed a sigh of relief at the final whistle to continue their bid towards a first Confederation Cup triumph.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)