A dull spectacle came to life in the closing stages when the former Celtic and Dundee United man curled the ball into the back of the net to earn his side all three points.
Lee Mair, playing against his former side following his summer switch to the Buddies, was given his marching orders for dissent after the goal to cap off a disappointing day for Gus MacPherson's men.
The Buddies, who were looking for their first win at Pittodrie since 1987, will feel hard done by to leave empty handed after enjoying a large amount of possession during the tense match.
Sone Aluko started for Aberdeen following his return from a Nigeria under-20 training camp yesterday. The midfielder had angered Mark McGhee by jetting out to join the Flying Eagles without his club's permission but returned late yesterday evening for clear-the-air talks with his manager.
Striker Darren Mackie and 16-year-old midfielder Fraser Fyvie dropped to the bench with Italian defender Davide Grassi starting for the Dons.
St Mirren made two changes to the side that drew 1-1 with St Johnstone last weekend. Garry Brady and Craig Dargo were preferred to Michael Higdon and Andy Dorman who both had to be content with places on the bench.
Aluko, playing on the right of midfield, looked eager to impress in the early stages but a woeful shot brought a darting run through the Buddies' half to a disappointing end.
The Dons should have taken the lead in the 10th minute but Paul Gallacher showed great reactions to keep out Lee Miller's close-range header and, with the goal gaping, Andrew Considine volleyed wide of the target from seven yards when it looked easier to score.
It was not until the 22nd minute when MacPherson's side made their first real foray forward with Dargo setting up Stephen McGinn who flashed an effort wide from the edge of the area.
The Buddies were coming more into the game as the half wore on and after 31 minutes McGinn unselfishly laid the ball into the path of Brady whose thunderous effort just failed to hit the target.
Some skilful trickery from Aluko earned the Dons a free kick in a promising position but Charlie Mulgrew, uncharacteristically, failed to get the ball beyond the first man.
Dargo's shot on the turn from a David Barron centre sailed harmlessly high and wide as the half drew to a close with St Mirren on top.
The Buddies made the early headway after the restart with Dargo again looking menacing as he neatly turned past Considine in the box before Jerel Ifil thwarted the former Inverness Caley striker as he was about to pull the trigger.
With his side looking second best, Aberdeen boss McGhee made an early change with Chris Maguire replacing Michael Paton after 52 minutes.
Barron, who had been booked in the first half for a reckless challenge on Aluko, escaped a second caution when he was penalised for handball after 57 minutes.
Aluko was looking the home side's most promising route to goal but Gallacher was equal to his fierce, low drive from 25 yards.
Mair was cautioned for a challenge on Miller after 75 minutes. From the resulting free-kick Mulgrew curled the ball brilliantly over the wall only to see it bounce back off the crossbar, and Miller was unable to divert the rebound past Gallacher.
The visitors made their first change of the day after 79 minutes with Andy Dorman replacing the tiring Dargo before the Dons replaced Aluko with Mackie three minutes later.
A wicked cross from Foster caused bedlam in the St Mirren box in the closing stages with Mark Kerr eventually firing over.
However, the Dons supporters were celebrating a winner soon after when, after Mackie had been fouled on the edge of the area, Mulgrew stepped up to curl home the winner.
To add insult to injury for the Saints, Mair was given a second yellow for dissent following the goal, much to the delight of the Red Army.