After Chris ANDERSON had given the homesters the 11th minute lead, Brian NEILL equalized after 26 minutes only for Chris MAGUIRE to make it 2-1 to the visitors three minutes later.
That was how the score stood until the 71st minute when, Michael PATON, who had replaced Willie John Kiely a minute earlier, pounced with almost his first touch of the ball. Athletic appeared to cave in after that and further efforts followed from Neil (84), Maguire (86) and Kyle MACAULAY (88) to complete Sandy Clark's team's biggest win of the season.
Williamson went off injured after 70 minutes but Dunfermline had already used their three substitutes.