The Buddies merited their victory in the end even if they had to survive a late Hibs rally before snatching a dramatic last-gasp winner themselves.
Mark O’Hara gave St Mirren an early lead from the penalty spot before Toyosi Olusanya doubled their advantage less than a minute later.
We came back with goals from Adam Le Fondre and Christian Doidge in the closing stages however, the afternoon would belong to the visitors as substitute Alex Greive headed in a late winner.
Lee Johnson made just one change following our resounding victory over Inter Club d’Escaldes on Thursday evening as David Marshall recovered sufficiently to start.
He replaced Jojo Wollacott in the starting XI whilst Max Boruc, who came on as a substitute on Thursday, took his place amongst the substitutes despite impressing against the Andorrans.
New recruit Dylan Vente is waiting on the completion of his work permit and was therefore unavailable for the league opener.
St Mirren were forced into a late change with Mikael Mandron picking up a knock and he was replaced with Olusanya.
We started brightly and carved out an opportunity inside the opening 40 seconds as Josh Campbell and Elie Youan linked well before the former stabbed wide.
The visitors then had an early chance when Richard Taylor’s header at the back post forced Marshall into a smart save.
Moments later a snapshot from Ryan Strain was bravely blocked by Paul Hanlon before the ball was recycled and a Greg Kiltie effort from the edge of the area was gathered by Marshall.
The deadlock would be broken on 15 minutes following the decision to award St Mirren a contentious penalty kick after Kiltie had gone down softly inside our area from Joe Newell’s challenge.
After a long review, the penalty was awarded, and O’Hara sent Marshall the wrong way to put his side ahead.
Less than a minute later and O’Hara turned provider as he brushed past Campbell and fed the ball into the path of Olusanya, who slipped the ball through the legs of the outrushing Marshall to double his team’s lead.
Whether it was down to our midweek exertions in Europe, or simply the performance of our impressive opponents, we were struggling to contain the pace and movement of St Mirren.
Johnson then made a double change replacing Allan Delferrière and Campbell with Dylan Levitt and Jordan Obita.
Stephen Robinson’s side were outstanding and almost grabbed a third before half-time when Strain’s dipping free-kick flashed just over the crossbar.
Shortly after the interval a long throw into the St Mirren box almost fell kindly for Will Fish, however it was just out of his reach and was fortuitously deflected into the arms of Zach Hemming by one of his defenders.
After a frustrating afternoon for Youan, he finally got some joy on 57 minutes when he burst clear of Taylor and into the St Mirren box before trying to squeeze a shot past Hemming at his near post that the goalkeeper did well to block.
From the resultant corner kick Fish rose highest to connect but could only divert his header wide of goal.
After an hour Boyle was replaced by Le Fondre as the veteran striker came on for his competitive Easter Road debut and his first taste of Scottish football.
He would make a quick impact as he latched onto Newell’s pass in the centre of the park, played a neat one-two with Doidge before finishing beautifully beyond Hemming and into the far corner of the net.
With the crowd roaring the boys on we pushed for a leveller with Doidge and Le Fondre going close with glancing headers.
Eight minutes from time we drew level when Youan’s driven cross was swept in from close range by Doidge to finally restore parity.
And it appeared if there was going to be one side that would go to win, it would be us, as Hemming produced a fantastic instinctive save to deny Levitt’s half-volley on 86 minutes.
Yet, the visitors had other ideas as Kiltie floated a delivery into our penalty box where substitute Greive found himself between two defenders and glanced a wonderful looping header over Marshall, into the far corner of our net. That proved to be the winning goal.
Hibernian: Marshall, Hanlon, Fish, Youan, Doyle-Hayes (Jeggo 81’), Boyle (Le Fondre 63’), Newell, Stevenson, Doidge, Delferriere (Obita 29’), Campbell (Levitt 29’). Substitutes not used: Boruc, Miller, Melkersen, Harbottle, McAllister.
St Mirren: Hemming, Fraser, Gogic, Taylor, Strain (Bolton 90’), Baccus, O’Hara, Kiltie, Tanser, McMenamin (Boyd-Munce 75’), Olusanya (Greive 67’). Substitutes not used: Urminsky, Flynn, Dunne, Nahmani, Jamieson, Kenny.
Referee: Euan Anderson.
Attendance: 17,586.