Dumbarton were 15 minutes away from their third away win of the season after controlling most of the action at Recreation Park, but a sensational late fightback saw Alloa burgle all three points.
Goals from Andy Rodgers and Ian Russell had put the visitors in what appeared to an unassailable position. And with the Sons having kept clean sheets in their two previous away games, there seemed to be no way back for a tired and dispirited home side.
An injury to striker Ross Hamilton then brought Alex McMillan on to the field, and after the substitute had pulled a scrambled goal back, the Wasps suddenly rediscovered their sting and equalised through a free header from Michael Bolochoweckyj before completing their comeback when defender Richard Walker blasted home a first time volley in the last minute of the contest.
Much earlier John Dillon had already struck the post for Dumbarton by the time Rodgers put them ahead after pouncing on a sharp headed passback by Bolochoweckyj.
Rodgers and Alloa's Mike Daly both missed clear-cut opportunities and Russell then saw a goalbound shot cleared off the line by Ian Nicholson.
Russell finally found the net after heading home a precise cross from Rodgers, and at that stage Alloa looked dead and buried.