A rare error from Aberdeen goalkeeper Joe Lewis proved costly as Aberdeen made an early exit from the Betfred Cup with a 2-1 defeat by St Mirren.
Ilkay Durmus gave Saints the lead from a free kick after only three minutes but Niall McGinn equalised just before the break.
But with only two minutes remaining a Jamie McGrath shot squirmed past Dons goalkeeper Lewis to send the Buddies into the last eight of the competition.
The Dons made two changes from the side that drew 1-1 with Hamilton Accies on Wednesday with Jonny Hayes and McGinn drafted into the line-up in place of Ash Taylor and Curtis Main.
Andy Considine started the match in his 535th appearance for the Dons as he moved to joint fifth alongside Jim Leighton on the club’s all-time list.
Aberdeen, playing their third away match in six days, started slowly and fell behind with only three minutes on the clock.
Hayes was penalised for a foul on Dylan Connolly as he advanced towards the Dons penalty area and Ilkay Durmus took full advantage with a curling free kick which found the bottom corner of the net.
It was almost 2-0 to the Buddies only three minutes later when Richard Tait’s fizzing drive from distance bounced back off the post.
The hosts had a penalty appeal when Jon Obika tumbled under pressure waved away as Aberdeen struggled to gain a foothold.
St Mirren went close to a second seven minutes before the interval when Connolly showed exquisite footwork to twist past Greg Leigh only to shoot straight at Lewis.
Aberdeen were living a charmed life as St Mirren striker Obika somehow prodded wide from only three yards out as the home side pushed for the second goal their dominance probably deserved.
But, against the run of play, the Dons levelled two minutes before half-time when a Hayes pass ricocheted off Cosgrove and fell kindly into the path of McGinn who kept his composure to slot past Jak Alnwick.
The Dons made a double change at the break with goalscorer McGinn and Sam Cosgrove replaced by Main and Mikey Devlin, making his first appearance of the season.
Tommie Hoban passed up a great chance to put the Reds in front only three minutes into the second half when he was left unmarked in the Saints penalty area but headed wide from a Ryan Hedges corner.
Substitute Main stung the palms of Alnwick with a rasping drive with Aberdeen looking the more likely to grab the game’s next goal.
St Mirren were also keen to avoid extra time with former Ross County captain Marcus Fraser testing Lewis with a low shot.
And it was St Mirren who were to grab the winner with Lewis unable to prevent McGrath’s shot hitting the back of the net.