Wydad began life under Juan Carlos Garrido, who pulled out a strong eleven with all their star men featuring against his former side.
Mohamed Nahiri got the home side off to an ideal start 11 minutes from kick-off after picking a ball from Ismail El Hadad to slot home from a set piece scenario.
Etoile found an opportunity to go level five minutes thereafter, but Mohamed Methnani's header from the centre of the area failed to find the intended target.
The Tunisians finished the half confidently with back-to-back attempts from Souleymane Coulibaly following the half-hour mark which forced the best out of Wydad shot-stopper Ahmed Tagnaouti.
Wydad looked to maintain their advantage two minutes after the break, as Walid El Karti created space around the centre of the area to bring Makram Bediri to a save.
The second goal arrived nearly 10 minutes into the second stanza after Nahiri completed his brace with a sharply taken header from Attiyat's delightful cross.
Etoile turned to the bench at the midway mark and introduced Bahaeddine Sellami and Yassine Chikhaoui who replaced Mohamed Konate and Mohamed Methnani respectively.
Nahiri closed in on a hat-trick towards the final 20 minutes, but his long-range strike proved no trouble for Bediri.
Wydad maintained ascendancy following the remaining minutes for a crucial first-leg victory with the return-leg set for next weekend.