Two fine goals and a brilliant penalty save were the highlights of a largely workmanlike Aberdeen performance that saw the Dons to another three points, making it 13 out of the last 15 as they maintained their three point gap over fourth place Motherwell.
After the draw at St. Johnstone last Sunday, Derek McInnes made three changes to his starting XI. Shay Logan, Michael Devlin and Curtis Main all dropped to the bench with Zak Vyner, Jon Gallagher and Dean Campbell coming into the team. James Wilson also returned to the action with a place on the bench.
Tenth placed St Mirren came into the game after losing to Hibs on Tuesday. They made just the one change with Andreu replacing Durmus, who took his place on the bench.
The afternoon started with a well deserved guard of honour from both sides for Andrew Considine after clocking up his 500th appearance for the Dons last weekend, followed by a special presentation to him from chairman Stewart Milne, Considine rightly drawing a standing ovation from all around Pittodrie.
Restored to the captaincy after Considine had the role last Sunday, Joe Lewis was in sharp action in the first minute, neat approach play from the visitors allowing Foley to put Andreu in on goal, the goalkeeper down sharply to his left with a fine save.
After a decent start from the opposition, Aberdeen's first real attack came in the sixth minute and it proved decisive. Dean Campbell collected the ball on the edge of the box and played a clever pass out to Jon Gallagher. He found Ryan Hedges who advanced to the by-line and though his cross was blocked, Sam Cosgrove controlled nicely with his first touch, his second a lovely calm finish, curling a well placed shot beyond Hladky with his left foot. Number 18 for the season.
Magennis went into the book in the 12th minute for a tug on Lewis Ferguson's shirt as he looked to drive the Dons forward, but the St Mirren man tried to hit back two minutes later with a low drive from a tight angle at the near post which Lewis shovelled wide of goal.
Brimming with confidence, Cosgrove had his eye on goal again in the 17th minute, a right footed 25 yarder well clutched to his left by Hladky. Sadly two minutes later, Cosgrove sliced wide from similar distance at the end of a great move that started with a long ball out from Scott McKenna to Niall McGinn. His cross was cushioned back to Cosgrove but the goal of the season contender didn't quite come.
It should have been two in the 22nd minute, another sweeping Aberdeen move allowing Vyner to sling a cross into the box from wide on the right, Ferguson hurling himself at the ball but getting his angles wrong, glancing the ball wide of goal when he perhaps should have buried the chance.
It was a costly miss for within a minute, a fine, mazy run from Flynn down the right saw him drive into the box to square the ball through the six yard box, Obika on hand with a deft finish to equalise.
They might have gone in front in the 33rd minute, McLoughlin given a free header from Waters' free-kick wide on the left, but fortunately, the centre-half put his effort wide of goal. The Dons won a first corner in the 35th minute, Hedges on the left finding Cosgrove at the back post, his header cleared off the line by Waters.
Andreu smacked wildly over the bar from distance in the 41st minute after Aberdeen were wasteful with possession, the hosts going through a scrappy period to the frustration of the crowd. All was almost forgiven on the break, but both Considine and then particularly McGinn were denied by fine last ditch defending. From the resulting corner in, Greg Leigh headed into the ground, Hladky grabbing the ball just under his bar, the last action of the half.
HALF-TIME: ABERDEEN 1 ST MIRREN 1
The Dons almost had the perfect start to the second half, Cosgrove directing a McGinn cross to the feet of Hedges who dragged his shot just wide of goal in the 47th minute.
A driving run from Ferguson won a free-kick right on the edge of the box in the 53rd minute, just to the left of the D from the Aberdeen perspective. Stephen McGinn blocked Ferguson's shot with his head before dropping to the turf and getting treatment, though he was soon able to continue.
Good work by the Dons - and by the referee who played the advantage - allowed Aberdeen to get back in front in the 56th minute. Persistence from Hedges took him past a foul tackle and into the box, from where he pulled the ball back to McGinn. His first touch gave him space to crack his second into the roof of the net, the 500th goal of Derek McInnes' Aberdeen reign.
St Mirren responded immediately and Obika's looping header in the 58th minute almost dropped into the net, Lewis scrambling across goal as it squirmed wide. The visitors continued to look anything but a team that had amassed just 11 points so far this season.
Campbell drilled at goal from a well worked corner in the 62nd minute, Hladky saving well, the Dons claiming a penalty for dangerous play as McKenna almost had his head taken off as he tried to get onto the rebound. St Mirren then introduced Durmas to the fray in the 63rd minute in place of Magennis. Logan was Aberdeen's first change eight minutes later, replacing Campbell as the game lost some of its zip.
With 15 minutes to go, St Mirren should have been on terms, Andreu free in the box just a dozen yards out, but with more time than he suspected, he hit his first time shot into the turf, from where it bounced up onto the roof of the net, a warning for Aberdeen. St Mirren then immediately brought on McAllister for Foley, the Dons responding by swapping Hedges for Connor McLennan. Substitute Durmus collected a yellow card for a late tackle on Ferguson with ten minutes left.
In the 82nd minute, Cosgrove did everything right but the finish, good control and a strong run taking him to the edge of the box, but his shot was weak, leaving McGinn to complain he didn't get the pass.
Up the other end and the Dons conceded a penalty, Obika nudging the ball past Lewis just inside the area before hurling himself to the ground at the slightest touch from the goalkeeper and winning a debatable penalty. Up stepped Andreu, Lewis making a great save to his right, then an even better one, still on the ground, as Andreu was quick onto the rebound, brilliant work from the skipper.
St Mirren had their tails up now though as the tempo of the game was raised into the final straight. Main came on for McGinn and Andreu was replaced by Morias in the 86th minute as both sides took a final throw of the dice, but to no avail from the visitors' perspective, the Dons seeing the game through to its close and to three more important points.