Stevie Mallan's 10th goal of the season from the penalty spot gave Saints the lead after Darren Brownlee fouled Lawrence Shankland.
The Doonhamers equalised when Gary Oliver headed in at the back post.
But within a minute Alex Cooper's cross was turned into his own net by Callum Tapping to restore the Buddies' lead.
St Mirren now trail fourth-placed Raith Rovers by 11 points with 24 still up for grabs, while Queen of the South are eight adrift of the Kirkcaldy side.
September 2003 was the last time the Doonhamers secured an away victory against St Mirren and there was no success in this eighth attempt at taking three points from Paisley.
It was on the half-hour mark when substitute Brownlee was dispossessed by Shankland and sent the on-loan Aberdeen striker tumbling as shaped to shoot.
Referee Alan Muir pointed to the spot and Mallan despatched the penalty low into the bottom left corner.
Prior to that, Queens had hit the crossbar from Kyle Jacobs' cross-come-shot but another of his deliveries helped bring the visitors level after the break.
Oliver popped up at the back post to nod in his third of the season - all the harder to take for Saints given they had just had a Shankland goal ruled out for offside moments before.
But a minute after Oliver's leveller, St Mirren regained the lead.
Cooper scampered down the left and his low, hard cross diverted off Tapping and into the back of the net.
Alan Gow almost added another for Saints at the end, but Queen of the South's Robbie Thomson made a superb diving save.
St Mirren's faint hopes of finishing fourth in the Championship were kept flickering by beating Queen of the South in Paisley.