St Mirren leapt into the top six after sealing a crucial home victory in the latest battle of the Saints.
It was a tale of two penalties in the first half, with Callum Hendry knocking St Johnstone in front at the second attempt after his initial spot-kick was forced to be re-taken.
Connor Ronan drew the Buddies level just before half-time, bagging his sixth goal in the stripes from the spot after Alex Greive was hauled down by Jamie McCart.
