Morton kept their promotion hopes alive with a last-gasp 3-2 Scottish Championship victory over Dumbarton at Cappielow Park.The visitors, who appear increasingly consigned to the relegation play-off, took a surprise 55th-minute lead when Danny Handling fired home from Grant Gallagher's pass.The lead lasted seven minutes before Gary Fraser latched on to Scott Tiffoney's pass before equalising from 12 yards.John Baird gave Morton a 69th-minute lead, smashing the ball into the top corner of the net following Tiffoney's corner.A Thomas O'Ware own goal three minutes from time looked to have salvaged a point for Dumbarton, but Jack Iredale slotted home the winner from six yards in the third minute of stoppage time.The result leaves Dumbarton eight points adrift of Falkirk with only four games to play, while Morton lie two points off a play-off berth.