The defending champions trailed 1-0 from the first leg in Tanzania, but levelled the tie at 1-1 on aggregate when left-back Sayed Moawad found the net in the 71st minute.
However, the Egyptian side could not break down the Young Africans' defence for a second time as the visitors held on to force a shootout.
But Al Ahly kept their cool under pressure to win 4-3 on penalties and avoid a shock elimination.
Last season's semi-finalists Cotonsport overturned a 1-0 first leg deficit to progress to the next round with an emphatic 5-0 triumph over Flambeau de l'Est.
Ephraim Yosanguim, Daouda Kamilou and Moussa Souleymanou all found the net to put the tie beyond doubt, before a double from Rostand Kako added the gloss to a fine performance.
Four-time winners TP Mazembe are also through thanks to a comfortable 3-0 success against Les Astres of Cameroon, which secured a 4-1 aggregate win.
The Congolese outfit too the lead after 31 minutes through defender Salif Coulibaly, and progression was ensured by further strikes from Jonathan Bolingi and Jonas Sakuwaha.
And there was more Congolese success as Vita Club edged Dynamos of Zimbabwe thanks to a 38th minute Teddy Etekiama penalty, the only goal of either leg.
Meanwhile, Roger Assale was the hero for Ivorian side Sewe Sport, his 44th minute strike earning them a 1-0 win versus Barrack Young Controllers of Liberia and a 4-3 aggregate scoreline.
Ahmed Zuway and Edward Sadomba found the net for Al Ahli Benghazi in their 2-0 victory over Berekum Chelsea after a 1-1 first-leg draw, while CS Sfaxien beat Dedebit 2-0 to seal a 4-1 aggregate triumph.
Elsewhere, Al Hilal Omdurman overcame Stade Malien Bamako 2-0, following a 0-0 draw last week.
