Ten-man St Mirren lost at home for the first time since January as Tom Walsh netted late on to give Dumbarton a 1-0 win.
The Buddies were reduced to 10 men minutes before the interval when Stelios Demetriou was given his marching order for a stray elbow on Sam Wardrop.
Ex-Saints loanee Tom Walsh scored the winner for the visitors with around 10 minutes to go to give them all three points. In truth, Dumbarton deserved the win on a day where the Buddies were flat.
It was Sons who started brightly with Walsh going close to giving them the lead inside the first minute, but Craig Samson did well to push behind for a corner. Walsh did well on 12 minutes when he broke free only to curl his shot straight into the arms of Samson.
Saints gradually started to grow into the game without causing Dumbarton too many problems. Stelios almost connected with a Kyle Magennis cross before the latter drilled just wide of Scott Gallacher's post from outside the area. From the Magennis effort, Sons broke up the park with Liam Smith having to make a vital intervention to deny Alistair Roy a free header at the back post.
Liam Smith almost nodded Saints ahead two minutes before the interval when his looping header went just over the bar.
The Buddies were reduced to ten men just before half-time when Stelios was shown a red card after elbowing Dumbarton defender Sam Wardrop. There were no complaints from the Cypriot as he marched off down the tunnel.
Half Time: St Mirren 0-0 Dumbarton
The visitors started the second half on top with a tame Walsh shot gathered easily by Samson before Roy headed just wide from Calum Gallagher's cross.
Stuart Carswell had a shot pushed away by the Saints keeper moments later and then, on the hour mark, Chris McLaughlin's decent run saw the full back shoot tamely into the arms of Samson.
Samson had to deny Walsh a few moments later which resulted in Sons being awarded a corner kick. McLaughlin rose the highest, but nodded just wide.
Alistair Roy should have put the visitors ahead on 73 minutes when he was played in by Walsh. The forward was one-on-one with Samson but somehow conspired to roll the ball past the post when it looked easier to score.
That miss seemed to jolt St Mirren into life with an increased sense of urgency seeing Liam Smith's driven ball into the box causing panic in the Dumbarton defence though they eventually scrambled clear.
With just 10 minutes remaining, Dumbarton grabbed the lead when Walsh's fine solo run saw him create space in the area before squeezing the ball into net at the right hand post.
Saints sent on Ross Stewart to play alongside fellow sub John Sutton but neither could help the Buddies muster up an opportunity to steal a point late on.
Full Time: St Mirren 0-1 Dumbarton
St Mirren: Samson, L.Smith, Baird, Davis, Eckersley, McShane (Stewart 82), McGinn, Morgan, Magennis, Stelios, Reilly (Sutton 75)
Subs Not Used: Stewart, Buchanan, McCart, Kirkpatrick, Stewart, Duffy, Sutton
Dumbarton: Gallacher, Barr, Dowie, Wardrop, McLaughlin, Walsh, Carswell, Hutton, Gallagher (Nade 71), Stewart (Roy 7), Morrison (Froxylias 63)
Subs Not Used: Ewings, Wilson, Johnston, Hill, Froxylias, Nade
Referee: Andrew Dallas
Assistant Referee: Willie Conquer
Assistant Referee: Daniel McFarlane
Attendance: 3,591
Gallery pictures by Allan Picken © - Allan Picken Photography
