The Pittodrie side had the vast majority of the play with Joe Lewis and then Tomas Cerny virtual spectators.
Early on both Graeme Shinnie and Scott Wright went close Campbell was unlucky with an effort which hit the post. Then Scott McKenna had a decent headed chance from a Shinnie free-kick.
It was therefore no surprise when Sam Cosgrove fires the Dons into a 39th minute lead. James Wilson, who had also gone close on a couple of occasions in the first half, played a nice through ball to Cosgrove, who shot low across the keeper into the far corner.
Five minutes after the restart man of the moment Cosgrove made it two with an unstoppable shot from an acute angle after a neat reserve pass from Mackay-Steven.
Midway through the second half, big Sam looked to have completed his hat-trick with a powerful header but the referee gave a free kick to the local outfit for something only he seemed to be aware of.
James Wilson and GMS had further chances as Aberdeen ran out comfortable winners in the end.
All of the squad who were fit to play were given a runout in front of 165 supporters, the majority of whom were there to see the Dons while there were no fresh injury worries for a relieved Derek McInnes who saw Cosgrove and skipper Graeme Shinnie yellow carded.