Hibs had been second best for long periods after the interval but Benjelloun showed that he is a star in the making with an opportunistic finish 12 minutes from time.
Hibs had come out of the blocks fast and looked hungrier than Hearts who were beset by their usual selection problems due to the politics that exists within the football club.
Three of the back four would not usually have started and Hibs took advantage of the makeshift defence with a string of promising attacks.
Craig Gordon made saves from Derek Riordan and Steven Whittaker and also grabbed a sliced clearance from Calum Elliot that was sneaking it in at the near post.
But Scotland's top stopper was helpless when Hibs grabbed the lead after 15 minutes. Jay Shields robbed Paul Hartley with a crunching tackle and Ivan Sproule whipped the ball into the middle.
Riordan's first touch left the ball behind him but he produced a sublime half-volley to put the home side in front.
Hibs continued to threaten and were visibly shaken when they conceded an equaliser a minute before the interval.
Robbie Neilson's long throughball saw Gary Caldwell and Zibby Malkowski collide, and Roman Bednar was able to take advantage with an easy finish from eight yards.
Hearts were the better side in the second half and Malkowski made a terrific stop to keep out Bednar's angled drive and Bruno Aguiar was only inches away from 25 yards as Hearts looked for the winner.
But Hibs' substitutions were to prove crucial as Scott Brown gave added stick to the midfield and Benjelloun pounced to strike the winner which means that the derbies in the league this season have ended honours even with two wins apiece.