Turriff nicked a goal mid-way through the second half to all but secure a fourth-place finish.
The match was decided by a free-kick from Lewis Davidson in a game where Fraserburgh’s William West missed a penalty and was then sent off.
The victory for Turriff all but secures fourth place as it would need a 23-goal swing and United to lose all of their remaining three matches for Inverurie to leapfrog them.
For the Broch it was a missed opportunity to climb up to seventh in the table following Nairn’s defeat to Formartine.
Fraserbugh started off the better of the two sides and went close on a couple of occasions early on, however nothing was really testing the experienced Kevin Main in the Turriff goal.
Mid-way through the first half Fraserburgh were awarded a penalty after referee Chris Phillips felt that Artjoms Kuznecovs fouled the versatile West in the area, much to the visitor’s dismay.
From the resulting spot-kick Main guessed the right way down to his right to make a save, as the penalty wasn’t struck with any conviction. That left the taker West with his head in his hands.
Minutes after the penalty, West had a chance to redeem himself when Ryan Cowie sent him through on goal one-on-one with Main. But similar to the penalty, West’s effort was weak and was easy for Main to save.
Going into the break the home side certainly had the better of the opportunities and dominated possession, but the score was still nothing each as despite their dominance the Broch couldn’t quite break down Turriff’s backline.
A quarter of the way through the second half the visitors were awarded a controversial free-kick about 20 yards out and with none of the normal set-piece takers on the pitch nothing much was expected.
Davidson hadn’t read the script though and hit a stunning free-kick over the wall and into the net to give United the lead against the run of play.
Mid-way through the half the visitors nearly doubled their lead but Nicholas Gray could only find the side netting from 10 yards out.
The Broch were then reduced to 10 men when West was dismissed after receiving his second booking, for handling the ball on the ground after he thought he had been fouled.
In the dying minutes United could have killed the game as Gray beat the offside trap which put him one-on -one with Joe Barbour in home net. The forward’s effort went underneath the young keeper but didn’t have enough power and was cleared by a defender.
In injury-time the home side were awarded a free-kick to the right-hand side. Ryan Cowie’s delivery was cleared away only as far Graham Johnston who found himself 12 yards out to the left of the box. But he hit the shot over the bar which basically summed up Fraserburgh’s night and left them rueing missed chances.