Dunfermline Athletic clinched the Ladbrokes League 1 title on Saturday after beating Brechin City 3-1 at East End Park.
That result, coupled with a 1-0 defeat for second-placed Peterhead at home to Cowdenbeath, means Allan Johnston's men cannot be caught.
Faissal El Bakhtaoui hit a hat-trick for the Pars, with Robert Thomson on target for a City side who slip back to the foot of the table.
Cowdenbeath were bottom at the start of the day but a first-half Greig Spence goal at Balmoor was enough to end Peterhead's 19-match unbeaten run.
It was third against fourth at Somerset Park where Ayr United beat Stranraer 2-1 with goals from Alan Trouten and Michael Wardrope. Ryan Thomson replied for the Blues.
The Lanarkshire derby at the Excelsior Stadium ended 1-1 to leave Airdrieonians and Albion Rovers three points outside the play-offs. Marc Fitzpatrick gave the Diamonds the lead but Ally Love equalised with 10 minutes left.
Colin McMenamin grabbed a late winner as Stenhousemuir beat Forfar 2-1 at Ochilview after Steven Craig had cancelled out Mark Gilhaney's opener.
