Formartine fought back to edge out Inverurie at Harlaw Park.
After a slow opening, the local derby ignited as Mark Souter and Shane Jamieson battled over a 50/50 ball. Souter was eventually penalised for the foul after the Formartine bench resumed their position on the sidelines following passionate protests.
The first half played out evenly with neither side forcing any early saves from the opposing keeper.
Locos could claim the best of the opening chances as Stephen Jeffrey floated a cross in for Andy Hunter, who tamely flicked the ball towards the top corner for Andy Reid to comfortably gather.
With little between the sides, it took an individual moment of magic from Colin Charlesworth to break the deadlock.
Charlesworth picked the ball up from Calum Dingwall in midfield and drove towards the Formartine goal, gliding past defenders before rooting Reid to the spot as he tucked his shot into the bottom corner.
Formartine quickly threatened as Locos looked to gather their defensive composure. Fortunately for Inverurie, Ross Anderson was on hand to block a curling Scott Barbour effort from the edge of the box.
United finally tested Scott Mathieson as Gary Wood shot low from 20 yards, and the keeper comfortably gathered the ball.
The reminder of the half played out with Inverurie holding the play in the centre of the pitch, rarely allowing any opportunities against them until seconds from half-time. Derek Young crossed deep into the box for Stuart Anderson, whose header was deftly tripped on to the crossbar by Mathieson.
The second half began much the same way for Formartine with their urgency instantly creating opportunities, as Jamie Masson powered down the right flank before cutting in towards goal. Spotting Mathieson coming off his line to close down the angles, Masson shot across goal only to see his effort run wide of the far post.
This pressure paid off within 10 minutes as Formartine tied the game with a simple route one move. Reid provided the considerable kick up the field for Barbour to control inside the Locos box. After composing himself in front of goal, Barbour wrong footed Mathieson before rolling the ball into the net, with Stuart Anderson claiming to have had the final touch on the line.
A shell-shocked Locos then gifted Formartine the lead two minutes later as Stuart Smith made an immediate impact off the bench. He provided an inch-perfect cross from halfway to find the Graeme Rodger around the penalty spot and the midfielder provided the perfect flick on to find the far top corner.
Unable to find a response, Inverurie struggled to get a foothold in the game as Formartine dominated possession in the second half, with any potential goal scoring opportunities immediately quashed.
With time expiring, the game was almost put beyond doubt as Wood held off Jeffrey as he walked the ball along the edge of the box, only for his resulting shot to be easily saved.