The match was fairly uninispiring from all parts. Brentford were expected to show more but Declan Rudd was rarely threatened throughout the game.
Preston started well and had numerous opportunities in the first ten minutes. North End had a shout for a penalty turned down when Maguire went down in the box.
Shortly afterwards the frontman converted when he latched on to a cross and created some space in the box to fire home from close range. The home sides then seemed to relax a little bit too much as the visitors came onto the home side.
Despite having possessions Brentford didn't create many real cut chances. They were made to pay in the second period when the keeper made a mistake rushing out to a ball.
As the defence tried to reorganise Fisher was found free on the right hand side. He slid a cross into the box where Barkhuizen tapped home for the second and decisive goal.
The win means Preston sit in fifth place in a congested early season table with most teams within a few points of each other. North End will hope to transfer their home form to their away form if they are to maintain a good start to the season.