The rout started after seven minutes when Bobby Linn was fouled by former Blue Toon player Gavin Beith with Linn dispatching the spot-kick himself.
It was 2-0 after 21 minutes when the lively Stuart McKay sqaured the ball from the byline for Graeme Sharp to side-foot home from close range.
McKay scored the goal he deserved after half an hour, pouncing on a defensive mix up to net from an acute angle.
The fourth goal was a superb solo effort from Linn who curled a shot into the net by the post after turning defender Alan Rattray.
Two minutes before half-time Keith Gibson latched on to a loose ball and shot into the net as the Forfar defence parted in front of him.
Gibson lashed in his second 11 minutes after the restart after some good work by McKay, with a Craig Tully header 10 minutes from time and a diving header from McKay in the 88th minute completing the scoring.
Forfar were issued with nine yellow cards by the referee which included two each for Rattray and Darren Gribben.