Saints sub Lewis Jamieson came off the bench to give Stephen Robinson’s side a late point – and sicken a vocal Hibs support who have now endures seven games without watching their side win.
Nick Montgomery’s side were left smarting after a game they looked to have a firm grip of got away from them in added time of what had been a pulsating encounter.
They were all set to move level on points with Hearts and into the top six after Josh Campbell had given them the lead in this game before Joe Newell had cancelled out Mark O’Hara’s second-half penalty.
But St Mirren, to their credit, kept pushing with Jamieson bagging a timely first goal for the club in the 92nd minute to maintain the impressive home form of the Paisley side.
Nick Montgomery threw in 16-year-old Rory Whittaker for his first start in a Hibs shirt as the Easter Road side looked to engineer a way up the table – and salve the bruises left over from the weekend Viaplay Cup semi-final defeat to Aberdeen.
St Mirren have been impressive on home soil with only Rangers taking full plaudits from Paisley.
It was the hosts who created the first real chance of note in the game with Greg Tanser letting fly from the edge of the box. It failed to do anything at all to trouble David Marshall in the Hibs goal but the stopper was called to muddy his gloves when he failed to deal with a high ball floated into the box.
He claimed – and received – the foul as Alex Gogic was closing in.
The Saints defender, though, was culpable at the other end as Hibs took the lead. Allowing a straightforward pass to run under his foot, Dylan Vente took full advantage to tee up Campbell who slotted past Zach Hemming.
Elie Youan was next up as he looked for joy from the edge of the box only to see his effort blocked.
With Hibs in confident mode, Jair Tavares picked out Vente but his shot was wide of the mark.
Hibs almost doubled their lead before the break with a trio of chances as teenager Whittaker and Vente had efforts blocked by Hemming.
Jordan Obita was forced into a goal-line clearance on the cusp of the break as Kiltie took aim.
Marcus Fraser went for the spectacular with a volley but Gogic almost gifted Hibs a killer second. The Cypriot internationalist dithered with a backpass as Campbell nicked in. Hemming saved his blushes as he darted off his line to get a hand in the way and deny Hibs.
St Mirren got a lifeline from the spot after VAR intervened to rule that Obita had pulled Richard Taylor to the ground in an off the ball challenge. From the spot, O’Hara duly converted with a composed, rifled finish.
Hemming had to tip away a low effort from Youan as Hibs rallied to come again and get themselves on the front foot.
It was a stay of execution as Hibs reasserted their authority with Newell finding the net to finish off a beautiful move. Youan had turned exquisitely before feeding Vente whose cutback was met in the six-yard box by Newell. It was no less than the Easter Road side deserved.
Saint tried to push for a leveller with substitute Alex Greive sending an effort just wide of the target.
Saints continued to push with the leveller coming from sub Jamieson in added time to break Hibs’ resolve. Youan gave the ball away with the 21-year-old making him pay as he rifled the ball past David Marshall.
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