Substitute Farid El Alagui prevented Hibs from crashing to their fifth successive Championship defeat, the striker’s late goal salvaging a point in Paisley.
And his strike means Hibs remain six points behind Falkirk with three games in hand in the chase for second place after the Bairns threw away a two goal advantage at Queen of the South.
But Alan Stubbs’ players headed for home convinced that but for a blunder by assistant referee Douglas Potter they could have won this match
Hibs were leading through Jason Cummings well taken goal when Potter failed to raise the flag as Buddies frontman Rocco Quinn, looking a good two yards offside, claimed the equaliser despite the furious protests from the Hibs players.
The Easter Road side, however, lost their way in the second half and the confidence seemed to drain from them when Lawrence Shankland drove a low shot into the far corner of the net to give Saints the lead.
But Stubbs went for broke, ending the match with four strikers and it paid off as El Alagui expertly swept Anthony Stokes’ low cross into the net.
Paul Hanlon returned to the heart of Hibs defence after a five match absence caused by a thigh injury, replacing Liam Fontaine who had picked up a similar, but slight, problem in training.
Other than a driven cross from Marvin Bartley which zipped across the face of the Saints goal, the pace on the ball eluding both Cummings and David Gray the first 25 minutes or so were totally unremarkable.
The Buddies made life tough for Hibs by deploying two ranks of four in front of goalkeeper Jamie Langfield forcing Cummings and Anthony Stokes to drop between the lines in an effort to create an opening.
But Alan Stubbs’ men did create their first clear-cut chance of the game in the 27th minute, Scotland internationalist John McGinn slipping a delightful ball through for Cummings to take first time with his left foot, firing it past Langfield for his 21st club goal of the season.
However, Saints equalised in controversial circumstances, Quinn looked at least two yards offside as Stuart Carswell’s header landed at his feet but assistant referee Potter refused to raise his flag as the midfielder swept the ball into the net from close-range.
The goal stood and Potter found himself surrounded by furious Hibs players while a clearly raging Stubbs gave him an earful when he got in range.
Hibs were certainly nursing a sense of a grave injustice as the second half got underway, Stubbs players determined to right that wrong and an inswinging cross from McGinn almost did it. Stokes was unable to make connection, but Langfield had to look sharp to use his feet to knock the ball clear of danger.
It was Saints, though, who got the next goal, Calum Gallagher’s pass finding Shankland in space enough for the striker to send a low angled shot across goalkeeper Mark Oxley and into the far corner of the net.
That goal seemed to sap Hibs confidence with the home side, who had largely been on the back foot in the opening 45 minutes sensing the game was very much in their hands.
St Mirren: Langfield, Watson, Baird, Webster, Irvine, Carswell, Mallan, Quinn (Thompson 76), Gallagher, Shankland, Cooper.
Substitutes not used: Willison, Goodwin, Gow, Agnew, Stewart, Morgan.
Hibs: Oxley, Gray, McGregor, Hanlon, Stevenson, Bartley (El Alagui 75), McGinn, Henderson, Boyle, Cummings, Stokes.
Substitutes: Virtanen, Handling, Gunnarsson, Dagnall, Thomson, Donaldson.
Referee: Craig Charleston.