This was one of those surreal footballing occasions where Posh could be relegated with a win and Forest able to seal a play-off spot even if beaten.
As it turned out, neither of those scenarios became reality with Forest taking victory to all-but secure their spot in the top six and the hosts’ inevitable drop back into League One coming on a losing note despite a late rally under current boss Grant McCann in a season when the damage was already done.
Forest frontman Surridge provided the only goal on the stroke of half-time when heading in his fifth goal of the season to leave Steve Cooper’s men almost certain of a play-off spot as they continue to dream of Premier League football for the first time this century.
There was considerably more at stake for Posh, though, on the day and they were the more threatening team early on.
Josh Knight saw a shot blocked by Djed Spence after a marauding run forward from the full-back before Brice Samba was called upon seconds later to ensure Forest did not fall behind.
The visiting goalkeeper dashed from his line to deny Ricky-Jade Jones after the Peterborough youngster collected a Harrison Burrows pass and turned a defender.
Forest showed signs of coming to life around the half-hour mark as Philip Zinckernagel provided a first test for Posh goalkeeper Dai Cornell with a shot from a tight angle – and the former was heavily involved when the only goal arrived in the 45th minute.
Zinckernagel stole the ball from Peterborough’s Knight and exchanged passes with Brennan Johnson during a lethal counter-attack that ended with the latter crossing from the left for Surridge to head back across goal into the corner of the net.
Posh responded by introducing striker Jack Marriott for the second half, but it was Forest firmly in the ascendancy.
Young defender Ronnie Edwards produced brilliant blocks to deny Surridge and Johnson further goals, while Zinckernagel steered an effort just wide before Cornell superbly kept out a Jack Colback blast midway through the half.
Creditably, Posh continued to search for a route back into the game, but it was with no success as Samba beat away shots from Sammie Szmodics and Burrows.
Forest substitute Lewis Grabban saw a late strike disallowed for offside before scuffing another glorious chance moments later before the replacement had to be substituted himself due to an injury.
But one goal proved enough to keep their promotion dreams on track, while Posh must plan for life in League One after just one campaign in the second tier.