The win that always looked like not being enough was achieved but the ultimate goal of getting promoted as champions was missed despite reaching an impress points tally.
76 points was enough to win the division two title four years ago by a comfortable 13 point margin but thanks to a dogged campaign by Montrose the Blue Toon will now need the play off route if the want to make a speedy return to League 1.
The home side came into the game on the back of a five match winning streak and got off to the best possible start taking the lead in the third minute.
A Willie Gibson corner from the left only just missed the head of Mason Robertson and that seemed to throw Patrick Scullion with the City player caught wrong footed almost on his own goal line and the ball trundled in off his shin.
They should have scored again in the 12th minute, the City defence failing to deal with a Gibson free kick and the ball broke to Robertson who crashed his shot off the crossbar with Rory McAllister failing get a shot off from the rebound.
The second half kicked off with the news that Elgin had taken the lead at Links Park but an equaliser soon dampened hopes of automatic promotion and there was still a worrying lack of urgency from Peterhead to get a second goal.
Inevitably super sub Jordan Brown came off the bench and he was soon in action inside the penalty area but took too long to try and shoot and a half chance was gone.
Top scorer Rory McAllister then ran clear but his delicate chip over the advancing keeper Callum Ansell drifted wide of the left hand post.
Then with eight minutes remaining and with the visitors not having had a single shot on target they equalised, the ball finding its way to Gareth Rodger from a corner on the left and he scored an unlikely leveller.
Drama in the dying seconds though when Scott Brown pounced to shoot home a winner and send his side into the playoffs on a high as they now meet Stirling Albion over two legs.