Saints slip out of the cup.
St Andrews United exited the Fife & Lothians cup when a much more clinical home team ran out comfortable winners.
The visitors had a number ofreasonable chances, but were unable to hit the target, and keeper Youssef Bejaoui did not have a save of note to make in the entire 90.
It was the 10th match this season that United have failed to score.
The home team should have taken the lead after only five minutes when Ryan McCallum headed a Ryan Gay cross into the side net when it looked easier toscore.
It was no surprise when Penicuik opened the scoring after 17 minutes.
A corner was not cleared by the visitors defence and Ryan Gay punished them by curling a shot past keeper Gavin Wilson from the edge of the penalty box.
A fewminutes later United had a great chance to equalise but as Craig Wedderburn stretched for the ball he was unable to hit the target.
The home team doubled their lead after 33 minutes when Aaron Sommervelle side stepped Danny Dobie and beat Gavin Wilson with a left foot shot.
United were reduced to 10 men after 62 minutes when Craig Wedderburn was shown a straight red card by referee Scott Millar for a tackle on Aaron Sommerville.
With seven minutes left on the clock Penicuik scored goal number three.
A free kick byNeil Jancyzk was headed across goal by Darrell Young to Aaron Sommerville and he scored from a few yards out.
Saints - Wilson, Brand, Dobie, Whitehead, Wedderburn, Rolland, Mackie, Patrick, (McInnes), Buchan, (Cunningham), Sibanda, (Sturrock), Deane.
Sub - Murdoch.