Raith drew first blood when Mark Stewart scored but Forfar were ahead by half-time through Lewis Milne and Josh Peters. Peters struck again in the second half and a Declan McManus strike was not enough to rescue Raith.
In a remarkable game at Cliftonhill, St Mirren beat Albion Rovers 4-3 after extra-time. Albion were 2-0 up through Ross Dunlop and Mick Dunlop but St Mirren hit back with three goals in eight minutes, from Lewis Morgan, Stevie Mallan and John Sutton before Dunlop equalised.
There were no goals in the second half but Lawrence Shankland headed Saints in front in extra-time before Mark Ferry was sent off for the home side for his second bookable offence.
Falkirk brushed aside Elgin City 6-1, goals coming from Bob McHugh (2), Myles Hippolyte, John Baird (2) and David McCracken, offset by a goal from Mark Nicholson.
Queen of the South thumped Stenhousemuir 7-1 at Palmerston. Stephen Dobbie scored twice as did substitute Steven Rigg and Dale Hilson, Grant Anderson, Derek Lyle (penalty) also netting.
Alloa Athletic continued their superb start to the season by taking care of East Fife 3-0 at home thanks to Jordan Fitzpatrick, Calum Waters and Greig Spence.
Queen’s Park upset Morton 2-0 at Hampden, with goals from Adam Cummins and David Galt, while Dunfermline Athletic eased into Tuesday’s draw with a 5-1 win at Brechin City, Lee Ashcroft scoring twice, and Stranraer shocked Dumbarton 1-0 at Stair Park through Mark McGuigan.