Falkirk beat St Mirren 3-2 in the Ladbrokes Championship to boost their hopes of finishing in second place behind Rangers.
Stevie Mallan’s double cancelled out goals from Lee Miller and Bob McHugh but Blair Alston grabbed a last-minute winner at the Falkirk Stadium.
Third-placed Hibernian went down 1-0 to relegated Alloa at the Indodrill Stadium - Michael Duffy was the matchwinner for the Wasps - and now trail Falkirk by six points.
In-form Raith Rovers can look forward to the play-offs after beating Queen of the South 2-1 at Palmerston. Craig Barr got the winner after Dale Hilson had cancelled out an early opener from Kyle Benedictus.
Morton defeated ninth-placed Livingston 2-1 at Cappielow with goals from Denny Johnstone (penalty) and Thomas O'Ware after Jordan White had given Livi a first-half lead.