Longside had Fraserburgh United as visitors on Saturday in Grill League Cup.
Butcher was first to have a real chance when he was sent clear in the sixth minute but the Broch defence got back to clear the danger.
A minute later the visitors forced a corner, Duffy held McLeman’s kick well under pressure from Watt.
Downie had a great chance when he got on the end of a Ritchie free kick but he fired the ball over the bar from eight yards.
At the other end Broch keeper Sinclair did well to clutch a Stainton corner.
A mistake in the Longside defence allowed Watt a chance but Duffy did well to block the shot.
A corner for United fell for Bisset but his shot was blocked by Stainton before the ball was cleared.
A 25-yard free kick from Duncan was blocked by the wall before being cleared.
The referee awarded a penalty to the visitors in the 30th minute with the Broch players thinking it was a goalkick, Donaldson was shown a red card in the aftermath before Watt fired the kick past the post.
Just on time Longside took the lead when a Norris shot was deflected into the air and Sinclair misjudged the bounce, Sean Butcher pounced to slot the ball home.
A dangerous cross from Calum Davidson found no takers and went out for a goalkick.
Minutes later the same player had a strike from the edge of the box but Sinclair was well positioned to make the save.
Fraserburgh had four corners in quick succession but the Longside defence stood firm.
The home side should have added to their tally in 64 minutes when a Bruce cross found Butcher but he scooped the ball over the bar from six yards.
Lawrence was sent clear minutes later but Duffy was again quick to block the ball and avert the danger.
Longside made a change in 72 minutes when Calum Davidson was replaced by Porter, they doubled their lead two minutes later when Ryan Duncan seized on a short backpass before being upnded as he rounded
Sinclair who was sent off for the foul, the forward made no mistake from the spot.
The home side made two more changes in the final ten minutes with Walker and Little replacing Butcher and Stainton.
Duncan did well when he got to the byeline and from his cross Walker saw his header cleared off the line.
This was a good result for Longside which sees them start the Grill cup with a win.
This was a welcome win as well after defeat in the opening two Superleague games.
Longside have two Grill cup games this week, tonight (Tuesday) away to Whitehills (kick-off 7pm) and then away on Saturday to Buchanhaven Hearts (kick-off 2pm).
LONGSIDE: Duffy, Whyte, Bruce, Beddie, Craik, Norris, Stainton, Donaldson, Duncan, Butcher and C.Davidson. Subs: Little, Porter, Walker, Gibb and Thomson.