There was controversy as early as the second minute when Karim Touzani was adjudged to have fouled David McKenna inside the area despite the infringement looking well outside! However justice was done when Derek Soutar produced a great save from McKenna's effort.
After a goalless first period, the Buddies went in front in 63 minutes when Marc MCAUSLAND's header from a corner was deflected into the net by Touzani. Ten minutes later though the Dons were level when Dyron DAAL took advantage of a poor clearance to slot the ball home past Chris Smith.
Saints restored their advantage four minutes later when Ian MAXWELL headed home a free kick and four minutes from time the home side scored again when MCKENNA slid in to convert a cross from the right.