The Moroccan took the game out of Aberdeen's reach as Hibs produced another polished performance.
Hibs had an early chance when Guillaume Beuzelin tested Jamie Langfield with a right-foot shot which the goalkeeper dealt with well.
But it was Aberdeen who moved in front in the tenth minute when Steve Lovell fed Barry Nicholson and he tucked the ball past Andy McNeil.
The lead was to last only three minutes as Steven Fletcher headed in a Dean Shiels corner for the equaliser.
Ivan Sproule saw a shot saved by Langfield but Aberdeen hit back and Lovell missed his kick in front of goal before Gary Dempsey curled a free-kick inches wide.
But Hibs moved in front two minutes into first-half injury-time with a sublime strike from Michael Stewart.
Shiels' corner picked him out five yards outside the penalty area and he produced a superbly controlled right-foot volley to leave Langfield with no chance.
Hibs went 3-1 up two minutes into the second half when a fine through pass from Fletcher freed substitute Benjelloun and he calmly rounded Langfield before netting.
He added his second ten minutes later with an 18-yard shot through the goalkeeper as Hibs booked their passage.
Chris Clark missed an open goal for Aberdeen late on to complete a miserable night for the Dons.