A first-half goal blitz saw Forfar 4-1 up at the interval and even when Raith reduced the deficit the Loons quickly replied to continue their steamrolling of the Rovers.
Man of the match Andy Jackson started the rout after only 40 seconds when he ran on to a fine pass from Barry Sellars and hit a low shot home.
Sellars himself added the second after some tragic defending from Chris McLeod before substitute Michele Lombardi made it 3-0 in the 32nd minute with a well-timed run before finishing high in the net.
Jackson got his second and Forfar's fourth three minutes later with a perfectly judged header which went over the keeper and just under the bar.
Mark Campbell pulled one back for Raith on the stroke of half-time before Paul McManus reduced the deficit further with a 61st minute penalty after Eddie Forrest handled in the box.
Forfar replied in perfect fashion, however, and just four minutes later killed the game with their fifth - the best goal of the night.
Jackson beat two men on the right before crossing for Sellars to fire in a first-time volley.
Keeper Alistair Brown parried but the ball fell to Darren Gribben and he kept his cool to beat his marker before netting.