Goals from former Cardiff striker Steven Thompson and a clinical strike from his midfield namesake Steven Thomson on the stroke of half-time consigned Hibernian to their second successive league defeat.
The Easter Road side were also left searching for their first home win of the season.
In an evenly matched opening both teams had their share of the chances.
The first of the match fell to Paul McGowan who shot high over the bar after meeting David van Zanten's cross.
For the hosts David Wotherspoon failed to hit the target from just outside the penalty area and Matt Thornhill's effort was easily gathered by Craig Samson in the St Mirren goal.
Hibernian's Garry O'Connor put the home side ahead after 25 minutes.
The striker fired home from just inside the area into the bottom left hand corner, leaving Samson in the St Mirren goal with no chance.
An unfortunate slip from Callum Booth after 41 minutes lead to St Mirren grabbing an unexpected equaliser.
Jeroen Tesselaar charged through on goal before unselfishly rolling the ball to former Cardiff striker Thompson who slotted into the empty net.
There were jeers from the home fans minutes later as Tesselaar robbed Victor Palsson before threading the ball through to Thomson who finished clinically.
Tesselaar was at the heart of all of the St Mirren attacking threat and his influence had helped Saints charge into an unexpected half-time advantage.
The second half was a much tighter affair with chances at both limited for both sides.
Colin Calderwood replaced Palsson with Danny Gilbraith but the midfielder struggled to make an impact on the game.
The Easter Road crowd vented their fury on several occasions - clearly disgruntled with their sides lack of attacking spark.
The introduction of Nigerian striker Akpo Sodje raised hopes of grabbing an equaliser but the best chance fell to fellow substitute Martin Scott who was unable to keep his shot down.