David Nugent started for the first time on his return to Preston. He added experience to the frontline and helped run Barnsley ragged in what was a terrible afternoon for the Tykes.
Preston should have put the game to bed before the break but somehow found themselves going in level. Maguire missed two gilt edged chances and there were other opportunities for Preston.
Johnson did give Preston the lead before the break with a header but the floodgates did not open. Instead Preston were careless from another corner allowing McGeehan to poke home from close range in what seemed like Barnsley's only attack.
North End did capitalise in the second half. Shortly after the break Barkhuizen was put through when he cooly slotted past the keeper to give Preston the lead.
Johnson extended the lead when put through. Pearson added another from close range before Harrop came on as a subsitute to chip home the fifth. There were other chances with Nugent missing a golden opportunity to score.
The visitors were too open and Preston sliced through them being clinical at times. The victory moves Preston into third ahead of the international break, one point off the league leaders having scored the most goals in the Championship this season.
After the break Preston will hope to build away at Reading before two tough home fixtures against Leeds and then the derby game against Blackburn at the end of the month.