The Algerian side were held 1-1 in the first leg in Brikama, but goals in either half helped avoid an upset with Zerrara's lofted cross finding its way into the net after 19 minutes.
Having failed to extend their advantage before the interval, captain Mellouli put the tie to bed early in the second half.
In Friday's other clash, AS Pikine failed to turn around their 5-1 deficit from the first leg as they were eliminated by USM Alger following a 1-1 draw in the return meeting.
After Aliou Sow gave the hosts slim hope at the Stade Demba Diop, Hamza Koudri drew Alger level and ensured a their progression to the last 16.
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