Two goals in the first half-hour gave Dumbarton their fourth win in five outings and saw them leapfrog their visitors into mid-table.
Skipper for the day Andy Rodgers gave the Sons a flying start when he raced on to a 40-yard Ryan Borris pass and first-timed a low drive past the helpless Francois Dubourdeau. The lead was almost short lived as Forfar raced to the other end, and Stephen Grindlay was forced to turn away a fierce effort by Loons' winger Ricky Waddell.
But with the wind behind them it was Dumbarton who dominated, and their second goal was no surprise. Again Rodgers was involved, playing a neat one-two with fellow striker Paul McQuilken who hammered the ball past Dubourdeau from the edge of the box.
Forfar picked up after the break, but despite, creating several chances for themselves late on as the Sons eased off, they failed to seriously trouble Grindlay.
The nearest we came to a goal in that quiet second period was a goal-bound header by Dumbarton's Jamie Smith, which was hooked off the goal-line by Davy King.