Exactly five months after it started in Dumfries, Saints completed the great escape by getting the point they needed against Hibs.
It wasn't easy – but then it never is where St Mirren concerned. After a goalless first half they were safe, despite 10-man Raith Rovers being ahead against Ayr. However, just after the break Grant Holt put the Championship winners in front and Saints were heading for the play-offs.
But the response from the Buddies was tremendous and they drew level after an hour, home-grown heroes Lewis Morgan, Kyle Magennis and Stevie Mallan combining for Rory Loy to score a priceless equaliser that sparked bedlam behind the goal.
And with Ayr equalising, that seemed to be that – only for Hibs to step things back up and the Honest Men to miss a penalty that the Saints fans had already celebrated as being converted.
Instead, Raith scored a last minute winner and three agonising minutes of stoppage time had to be endured before ref Alan Muir finally put Saints out of their misery by blowing his whistle to mark the end of the season and the completion of Mission: Impossible.
Saints boss Jack Ross stuck with the side that had demolished Raith a week earlier, hat-trick hero Stevie Mallan starting alongside Stephen McGinn in midfield. The skipper's brother John was in the Hibs team along with fellow former Buddie Darren McGregor.
A point was enough to keep Saints up but they should have been behind after just three minutes. John McGinn's tremendous cross field ball found Holt and the experienced striker knocked it down for the unmarked Andrew Shinnie, however he blazed over when he should at least have worked Billy O'Brien. The Buddies had struggled in the opening quarter of an hour but had a penalty claim when Morgan got the better of David Gray and then hit the deck under a challenge from the Hibs fullback, however ref Alan Muir curiously gave a goal-kick.
Gradually Saints began to settle and started to pose a few questions of the home defence. Gary Irvine ended up in the book for a foul on Martin Boyle – somewhat unfortunate considering Saints only lost possession when the referee got in the way. The free-kick came to nothing, Mr Muir perhaps feeling guilty and immediately blowing for a foul on Jack Baird when the ball was swung in.
Stephen McGinn had a tame shot blocked before Irvine's day was done as he failed to shrug off an injury and was replaced by Stelios just before the break. He arrived just as Saints forced a couple of corners and when the second was only partially cleared Mallan pulled it back for Morgan but he curled his shot over. In stoppage time the winger was clattered by Holt, earning the Hibs frontman a booking.
The striker made amends in the best possible way just a couple of minutes after the break. John McGinn curled in a great cross and Holt got on the end of it to divert it past O'Brien. With Raith winning against Ayr despite being down to 10 men, Saints were heading for ninth place. They were in danger of going even further behind too, Cummings heading over as the visitors struggled to stop crosses coming into their box.
A Stephen McGinn ball sparked them into life, Morgan causing Efe Ambrose problems and finding Loy with a low cross but his shot was blocked by McGregor. Jack Baird shot over from the edge of the box before Loy went close again, Magennis sending him away only for the on-loan striker's shot to be blocked by Ofir Marciano at his near post.
Mallan then got his first sight of goal but shot over before Saints deservedly drew level. Stelios' clearance found Morgan and he ran across the pitch before Magennis. He had the ball stolen off him by Mallan and as he shaped to shoot he had the ball nicked away by Loy who calmly slotted it across Marciano into the far corner. The Saints fans behind the goal went bezerk as their side found themselves half an hour from safety.
The job wasn't done though, O'Brien needing two attempts to save Martin Boyle's shot as Hibs got going again. The champions had perhaps gone to sleep after their goal but were showing they planned to finish the season on a high, however the away fans' mood was buoyed by news Ayr had equalised against Raith.
O'Brien did well to punch away a Cummings free-kick before Hibs replaced Andrew Shinnie with Keatings. Baird then saw his deflected shot saved by Marciano, before the Saints fans celebrated Ayr getting a penalty – only for it to be missed. The mood almost darkened further when it looked as if Cummings had scored but his shot whistled narrowly past the post. Jordon Forster, who'd come on at the break, headed from a corner as Saints found themselves clinging on before Loy was booked for fouling the other half-time sub Fraser Fyvie.
The Buddies replaced Cammy Smith with Rocco Quinn before John Sutton took over from Loy with three minutes left. It looked as if Saints would do it but there was bad news from Fife as Raith snatched a last minute winner. Suddenly the Buddies were a goal away from being dragged into the play-offs but they ran down the clock superbly in the corner before conceding a goal kick.
That was the signal for Mr Muir to take the ball and blow for full-time, much to the delight of the Saints players, management and fantastic supporters. From 19 points behind Raith, the Buddies had finished ahead of them, Ayr United and Dumbarton to ensure there will be Championship football in Paisley next season – and who thought we'd be saying that on that cold, dark Tuesday night at Palmerston in December?
Full Time: Hibernian 1-1 St Mirren
St Mirren: O'Brien, Irvine (Stelios 43), Baird, MacKenzie, Eckersley, Smith (Quinn 84), S.McGinn, Magennis, Mallan, Morgan, Loy (Sutton 88)
Subs Not Used: Langfield, Webster, Fjelde, Todd
Hibernian: Marciano, Gray (Forster 45), Ambrose, McGregor, Stevenson, Boyle, J.McGinn, Bartley (Fyvie 45), Shinnie (Keatings 76), Holt, Cummings
Subs Not Used: Laidlaw, Humphrey, Graham, Martin
Referee: Alan Muir
Assistant Referee: Willie Conquer
Assistant Referee: Alan Hogg
Attendance: 19,764