Ola Aina's stunning first-time effort set the wheels in motion with just five minutes gone, before Emiliano Martinez parried Orel Mangala's fierce strike over the line early in the second period to help the Tricky Trees create some breathing space in the bottom half and put a dent in the Lions' top-four aspirations.
Following his howler in last weekend's 3-0 defeat to Liverpool, Matt Turner watched on from the bench as Odysseas Vlachodimos was brought in for his maiden Premier League debut, and the Greek stopper was on course for a dream debut after just five minutes.
Anthony Elanga - fully recovered from illness - burst away from Matty Cash down the left-hand side and laid off Harry Toffolo, who picked out Aina to direct a crisp side-footed strike into the bottom corner from the edge of the area.
The left-back's maiden Tricky Trees goal was no less than Steve Cooper's men deserved, and the hosts tried to release Taiwo Awoniyi through the middle on a few occasions, but an overhit pass or the offside flag saved Villa's bacon as Unai Emery persisted with a high line.
Aston Villa were unsurprisingly having most of the ball, but it took until the 36th minute for the visitors to finally test Vlachodimos, who denied Nicolo Zaniolo at his near post following good work from Ollie Watkins and Moussa Diaby.
Both sides had penalty appeals waved away just before the half-time whistle blew, with Awoniyi being felled in the box but Nicolas Dominguez being penalised for an offside, while Toffolo was deemed not to have handled Lucas Digne's cross.
For the second week in a row, Emery brought off Zaniolo for Leon Bailey at the break, and the Lions boss witnessed his side come close to an equaliser in the 47th minute, but Vlachodimos again covered his near post well to keep out Watkins.
Only a matter of seconds later, the Forest goalkeeper witnessed his counterpart and Yashin Trophy winner Martinez make a terrible blunder, as the Argentine would seemingly palm Mangala's drive harmlessly over for a corner.
However, Martinez could only parry the midfielder's venomous drive into the air and over his own line - akin to one of the goals he conceded during Arsenal's infamous 7-5 EFL Cup win over Reading in 2012 - and despite a VAR check for offside against Awoniyi in the build-up, the goal stood.
Villa were not short of chances to cut the arrears in half, but Vlachodimos's gloves largely remained clean, barring one 67th-minute curler from Diaby which fell kindly into the 29-year-old's arms.
Profligacy was also harming the Lions' prospects of a fightback, as several more second-half attempts from Emery's side flew wide or over the crossbar, and Forest easily dealt with a succession of corners from their toothless visitors.
A first top-flight win since September 2 has seen Forest shoot up four places to 12th ahead of next Sunday's trip to West Ham United, while Villa remain fifth - having missed the chance to rise into the top four - and will look to redeem themselves at home to AZ Alkmaar in Thursday's Europa Conference League group-stage clash.