Saints academy kid Lewis Jamieson rode to his side's rescue with a dramatic late leveller against Hibs.
The Leith side were looking to make it back-to-back wins against St Mirren, having denied Stephen Robinson's men a trip to Hampden in the League Cup with their 4-2 win in September.
The home side were surprisingly sluggish on their return to action last night after a weekend without a fixture, with Alex Gogic giving his former side a head start with an uncharacteristic mistake that led to Josh Campbell slotting in the opener.
The Buddies were handed a lifeline when VAR awarded them a penalty from nowhere in the second half, with Jordan Obita pinged for a pull on Richard Taylor. Mark O'Hara made no mistake from the spot to pull his side level.
St Mirren looked on course to suffer a third defeat of the season when Joe Newell put the finishing touch on an excellent move.
But substitute Jamieson had the final say in injury time, the 21-year-old seeing his first effort blocked before calmly slotting past David Marshall to bag a very memorable first goal for the Paisley club.
Saints midfielder Keanu Baccus was fit enough to return to the bench, with Mikael Mandron's power preferred to Toyosi Olusanya's pace from the start.
The atmosphere was surprisingly subdued early on in Paisley, not helped by the PA system at the SMiSA giving up the ghost in the build-up to the match.
Scott Tanser tried to raise the decibel levels early on but his powerful drive flew well wide of the post.
After an uneventful 10 minutes the visitors were handed a lead from a costly and uncharacteristic Saints' error.
A simple Jordan Obita pass looked easy enough to clear but somehow the usually reliable Alex Gogic produced a howler, lifting his foot over the ball to allow Dylan Vente through on goal. The striker wasn't one to look a gift horse in the mouth, slipping in Campbell who fired well into the low corner past Saints keeper Zach Hemming.
Richard Taylor produced a crucial block to deny Elie Youan shortly after as Hibs threatened to double their lead.
Busy Youan saw two more shots blocked as St Mirren eventually scrambled clear, with Hemming making a strong stop in the middle of a good old fashioned stramash.
Hibs were far and away the better side in the first half, constantly probing a surprisingly sluggish St Mirren defence.
Campbell was finding far too much space in midfield. His cut-back to Youan saw the Frenchman curl narrowly wide with Hemming this time rooted to the spot.
The Saints finally started to show signs of life towards the end of the first half. Mandron directed a header over the bar from an accurate Scott Tanser cross, but in truth the effort was never really troubling David Marshall, who spent the majority of the first half watching comfortably on from his box.
Caolan Boyd-Munce produced a speculative effort from distance that sailed into the Hibs fans behind the goal, with Greg Kiltie's low drive inside the box the closest the Buddies' came to troubling the scoresheet in the first half.
Marcus Fraser was almost an unlikely goal hero as his powerful volley from the edge of the box sailed narrowly wide as the Saints started the second half with a lot more intent.
Gogic then had Hemming to thank for sparing his blushes for a second woeful mistake of the match. The Cyprus international tried to shepherd the ball back to his keeper but sold him short, with Hemming pulling off a fine stop to deny Campbell a second.
The Buddies were handed a lifeline when VAR intervened after spotting a foul in the Hibs box, Jordan Obita naively pulling Richard Taylor to the ground off the ball.
Mark O'Hara showed his penalty prowess once again, confidently sending Marshall the wrong to haul his side level.
Hemming got down well to his near post to deny Youan as the Saints keeper again came to his defence's rescue.
Robinson turned to his bench to try and force a winner, with Baccus replacing Boyd-Munce in midfield and Mandron making way for Olusanya up front.
Unfortunately for the hosts the changes had the opposite effect when Youan spun away from Taylor to create space in the final third.
He slipped in Vente who had the simple task of squaring to Newell at the back post, with the midfielder making no mistake from six yards out.
Forwards Lewis Jamieson and Alex Greive entered the fray with 15 minutes left on the clock, tasked with being a late hero for the Buddies.
And Jamieson almost provided the spark the Saints needed after just one minute on the pitch. Picking up the ball on the left flank, the youngster guided a terrific cross into the corridor of uncertainty, with Olusanya not connecting with his header by a matter of millimetres.
Greive was inches wide himself shortly after, turning his marker well before drilling a low shot agonisingly wide of the far post.
In the end it was Jamieson that made his mark on the game as it ticked into injury-time. The ball fell kindly to the striker from a Youan mistake and, despite his first effort being blocked, the youngster kept his cool to slot past Marshall and send the Saints' support wild.
It could have got even better for the home fans when the ball dropped to Baccus on the edge of box even deeper into injury time but the Aussie blasted over the stand, with Saints still leaving the ground more than happy having rescued a point.
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