However, their victory should have been far more comfortable and they sweated out the final moments after a bizarre Peterhead goal a minute before full-time.
Barry Sellars fired Forfar ahead after 16 minutes when Allan Youngson failed to clear a cross.
Eddie Forrest doubled Forfar's lead in the 33rd minute with the simplest of tap-ins after visiting keeper Paul Mathers could only parry a Sellars header.
A minute before the break Martin Wood pulled one back after he slipped his marker in the home box.
However, the home side restored their two-goal advantage within seconds when Martin Cameron powered home a header from a Ricky Waddell cross.
Forfar were denied what looked a clear penalty in the second half after Cameron was pulled back, but referee Mike Richee awarded a free-kick inches outside the area.
A minute from time Peterhead were awarded a goal on the say of the assistant referee, who decided a tame effort from substitute Scott Michie had crossed the line to the disbelief of almost everyone in the ground.
Despite the nervous finish Forfar held on for the win.