Culter made it through to the quarter-finals of the Grill League Cup as the best runners-up and will now face Dyce away next Saturday (September 8).
The Deesiders recorded their second win over Glentanar in five days with the game at times being played in monsoon conditions.
McBain latched onto a defensive slip in the opening seconds but his lob just drifted wide of the post.
Youngson then tried his luck, chesting down a Robertson pass before blasting a volley over.
The heavy rain started as McBain went racing down the right wing and his low cross was touched goalward by Youngson, Stewart in the home goal could only palm the ball to Ian LEITH who had the simply task of slotting the ball into the empty net.
The underfoot conditions were causing plenty of problems for the players but a stray McArthur pass found Megginson whose 20 yard shot just dipped over the bar.
Culter doubled their lead in the 33rd minute when McBain beat the offside trap before cutting the ball back into the path of in-form striker Jamie McALLISTER who scored at the second attempt.
Megginson again shot wide in a rare home attack before a Youngson piledriver was blocked at the other end.
McBain was left in space but saw his shot again blocked by Stewart and then McBain combined with McAllister who shot over just on the half time whistle.
After the break, Dawson played in Adams whose first time shot scraped the Culter post to safety.
Leith then tried his luck with a low 20 yard drive that was gathered by Stewart. At this point the winger was replaced by new signing Michael Taylor.
Youngson sent a terrific pass to McBain who raced onto goal but home keeper Stewart was quick off his line to foul the winger and up stepped Jamie McALLISTER who dispatched the ball into the net from the penalty spot.
Reid produced a great last minute tackle to deny Dawson and then Farquhar palmed away a rasping Adams effort.
Darren McAllister and McWilliam were introduced to the rain but it was the other sub Taylor thought he had beaten Stewart but his shot was cleared off the line in the 73rd minute. Dawson’s clever flick was hit first time by Taft but his shot was brilliantly turned away by Farquhar.
lentanar knew it was not their day when a mad scramble in the away box saw the ball saved, blocked and then kicked off the line for what would have only have been a consolation goal.
Taylor powered a 20 yard effort past the post then McBain saw his back post header saved.
McWilliam was next to fire wide but in the 84th minute Youngson’s through ball found George McBAIN who outstripped the home defence, rounded the keeper and then fired home from a tight angle to finish the scoring.
There was still time for Stewart to save from Taylor and Darren McAllister before the final whistle as Culter squeezed into the last eight on goal difference.