Grayson named an unchanged team although Jermaine Beckford returned to the bench after a month out with an ear infection. The side now looks settled and a match for anyone in the division again after a poor January.
Oldham made a basic error in the opening minute which allowed North End to take the lead and put a marker down. Gallagher swung in a corner and Huntington was allowed to roam free to head home from close range.
Shortly after Oldham went on the attack with Huntington booked for a bad challenge. Nothing came of the resulting free kick and from that point on Preston dictated play.
Johnson scored his thrid in as many gamed with a sweet left foot shot from outside the box which looped over the Oldham keeper. The youngster has already paid back his £50,000 fee.
The pith was not conducive to good football although the home side did try to get it down and play towards the end of the first half but the Preston defence kept the home side at bay.
The game was over early in the second half when Robinson crossed over a keep who was in no man's land. Garner chested into an open net from less than a yard out. Robinson was having a good game terrorising the Oldham defence.
Preston made it four when Ebanks-Blake on as a sub beat the Oldham keeper to the ball. He laid it back for fellow substitute Beckford who slotted the ball home for a goal on his return.
Other results meant that Preston went level on points with MK Dons who they play next Saturday. North End are ahead of Swindon and have a game in hand on both sides above them in the table with Preston sitting 8 points behind the leaders Bristol City.