Birthday boy Andy Considine was ordered off within minutes as former club Aberdeen celebrated a one-goal win in Perth.
Ten-man St Johnstone were unable to keep the Dons from opening their account on the half hour mark through a combination of Angus MacDonald and home goalkeeper Remi Matthews.
There were plenty of battling qualities on show from Callum Davidson’s side but, short of a player, they were unable to haul themselves back into the contest - despite a late push.