Arbroath have been crowned League 2 champions.
The Lichties drew 1-1 at Stirling, while Forfar — for so long out in front — lost 4-2 at home to Annan.
The final whistle sparked wild celebrations, as hundreds of Red Lichites’ fans poured on to the pitch to celebrate.
Montrose join Forfar in the promotion play-offs following a 1-1 draw at home to Clyde.
Cowdenbeath, meanwhile, will face a play-off to retain their League 2 status following a 0-0 draw at Elgin.
In the Championship, Raith Rovers face a relegation play-off despite a 2-1 victory at home to Ayr United as St Mirren’s remarkable escape was completed following a 1-1 draw at Easter Road.
Dunfermline secured a fifth place finish following a 1-0 victory away to Queen of the South.
Brechin’s place in the League 1 promotion play-offs was confirmed following a 1-1 draw away to Stenhousemuir, but East Fife lost out following a 2-1 reverse at Stranraer.