The Algerian - signed last week from Olympiacos - could not miss from a yard out, but his strike sealed another three points as Billy Davies' side eventually wrapped up another win against plucky Yeovil.
Jamie Paterson's sixth goal in six games put Forest ahead, but Keiffer Moore levelled things up, with Simon Cox netting again to restore their lead before Djebbour's stoppage-time effort sealed it.
Forest handed a debut to on-loan Southampton left-back Danny Fox, while midweek goal heroes Cox and Jamie Mackie, as well as Henri Lansbury, were recalled to the starting XI.
Jack Hobbs was not included in the squad after finally completing a permanent move from Hull.
Yeovil made just the one change from their defeat at Derby, with James Hayter coming in for Ishmael Miller, who was ineligible against his parent club.
Lansbury curled a shot inches wide of Marek Stech's left-hand post inside two minutes and Paterson's shot was blocked as Forest started like a house on fire.
There was a real sense of optimism amongst the Forest faithful, with popular chairman Fawaz Al Hasawi lapping up the applause as he stood up and saluted the crowd as they chanted his name.
After dominating for the opening 10 minutes, sloppiness at the back from Forest nearly let in the Glovers for a shock lead, with the ball eventually being fed to Moore who fired just wide from the edge of the box.
But after 16 minutes, Davies' side took the lead.
They broke with pace, and Lansbury delivered an excellently-weighted ball for Paterson who crashed a shot goalwards, with defender Byron Webster helping his effort into the net as he attempted to clear.
After Cox just failed to get on the end of Andy Reid's cross, Yeovil upped the ante and Hayter saw a well-struck drive saved by Karl Darlow.
The visitors were enjoying a sustained period of pressure and they stung Forest with an equaliser after 25 minutes.
Jamie McAllister produced a cross from the left and Moore out-jumped Darlow to head the ball into an empty net.
Seven minutes from the break, Forest were back in front with their first real attack since being pegged back.
Paterson's shot was only parried by the diving Stech to Mackie who crossed for Cox to stab home from four yards out.
In first-half stoppage-time, Mackie should have made it 3-1 as he latched on to Shane Duffy's poor backpass and bore down on goal only to rifle his effort into the side netting.
Lansbury's drive was tipped round a post by Stech as Forest created an opportunity after the break and then Reid played in Paterson, whose precise shot hit the far post and rebounded to safety.
Energy and creativity, though, were distinctly lacking from both sides throughout the second half, with goalmouth action a rare commodity.
Forest boss Davies sent on both Darius Henderson and Djebbour in an attempt to inject new life into his side, but it was Town's Joe Edwards who nearly lit the blue touchpaper as he forced into Darlow into a rare save.
Lawrence launched a free-kick in a dangerous area way over the bar and then McAllister's shot was deflected behind for a corner as Forest began to toil.
But they picked up late on and after Reid went close, Djebbour prodded home from a yard out following a goalmouth scramble to rubber-stamp the win.