Both sides took time to settle as the surface was making passing very difficult.
Leith was presented with the first chance on the quarter hour mark but didn't connect cleanly.
McMillan had a header over the bar from a corner before Cowie eventually found a way through Ferryhill's stubborn defence.
Adie played a ball long through the middle which was completely misjudged by the centre half and MCCOY clipped the ball over the keeper into the net.
Two minutes later Cowie should have doubled their lead, Matthews providing a pinpoint pass to release Adie who struck the shot sweetly but pulled it wide of the target.
McMillan's pace and strength was causing the home side problems and he created Cowie's next opening, sweeping in great cross from the right which Leith almost got in the end of.
Hudson broke from midfield and his stinging shot somehow went past the upright with the keeper stranded.
Right on the stroke of half time Grant was played clear of the defence but his low drive was blocked by the advancing keeper.
Cowie dominated the first half with Milroy having his quietest 45 minutes of football in along time.
Cowie came straight out of the blocks for the second half determined to put the game beyond the reach of Ferryhill.
With two minutes gone McMillan broke clear and his first effort was blocked by the keeper his next came off the hand of a defender with the referee having no hesitation in pointing to the spot.
Skipper MATTHEWS stepped up and despatched the ball into the net sending the keeper in the wrong direction.
Cowie pressed the game and Grant tried his luck from outside the box only to see the ball shave the post on its way out of play.
From the goal kick the ball went straight to Adie and his first time lobbed ball was met perfectly by GRANT who only needed one touch from 12 yards out to delicately volley the ball over the head of the keeper who watched helplessly as the ball nestled into the net.
Ferryhill did get a consolation goal with a superbly struck free kick into the top right hand corner which Milroy never got close to.
This win sees Cowie right on the heels of the teams above them in the league and keeps their promotion hopes alive.
Their next fixture sees them on their travels on Saturday to face Theologians in the 3rd Round of the AFC Trophy which is a 2 pm kick off at Alton.

Final Score: Ferryhill 1 - Cowie Thistle 3