Craig Moore, pictured, put them in front after half-an-hour and Declan McDaid doubled their advantage six minutes later.
There was no way back for Forfar and Robbie Crawford added a third with ten minutes left.
Albion Rovers recovered from their dismal opening day by beating Queen’s Park 5-2 at Hampden. Sean Burns put Queen’s Park in front after eight minutes but Jason Marr equalised six minutes before the break and Alan Trouten put Albion in front moments later from the penalty spot.
Connor Shields notched his fifth goal of the season to make it 3-1 when he swept a 15-yard shot beyond Alan Muir.
Shields scored his second to take the game out of Queen’s Park’s reach midway through the second half and Trouten also scored his second from a Ryan McManus pass for Albion’s fifth. Thomas Orr pulled a goal back but it was no more than a consolation.
Lewis Vaughan hit a double as Raith Rovers proved too strong for Stranraer at Stark’s Park, winning 3-0. He opened the scoring three minutes from half-time for his sixth goal of the season.
Greig Spence made it 2-0 with a tap-in and then Vaughan secured the points when he netted a third with the Stranraer defence appealing for offside.
Airdrieonians and Arbroath shared a 1-1 draw at the Excelsior Stadium. Omar Kader gave Arbroath a half-time lead with his 33rd-minute strike but Andy Ryan equalised five minutes into the second half.
East Fife edged Alloa Athletic 1-0 at Bayview. After a goalless first half, East Fife secured the points when Greg Hurst, who had hit the bar after a free kick in the first period, was presented with a simple opportunity after a mistake by goalkeeper Neil Parry.