Kyle Jacobs' early header for Morton was cancelled out by Alan Trouten and Kevin Cawley made it 2-1 to Alloa before the home side scored three times in the space of five minutes to lead 4-2 at half-time.

Luca Colville made it 2-2 in a see-saw encounter and goals from Morton pair Reghan Tumility and Bob McHugh put the hosts in control.

But Alloa reduced the deficit through Kevin O'Hara in the 85th minute and Deas headed home Cawley's cross in added time.