Danny Lennon's side reached the final of the Scottish Communities League Cup with a 3-2 victory over Celtic on Sunday and Steven Thompson's late header earned the Buddies their second win in four days.
Esmael Goncalves latched on to Paul McGowan's through-ball to net on his home debut and open the scoring midway through the first half.
That was then cancelled out on the stroke of half-time when Billy McKay netted his 20th league goal from the penalty spot after Conor Newton felled Richie Foran inside the box.
Inverness enjoyed the majority of the possession in the second half, however they were punished with nine minutes remaining when Thompson beat Antonio Reguero after connecting with Gary Teale's pinpoint cross.
The opening minutes offered little to warm up the fans who had ventured out on a bitterly cold evening in Paisley.
A wonderful 30-yard free-kick from Owain Tudur Jones after six minutes had both sets of supporters on their feet, though. The Welsh midfielder blazed an effort towards the top corner, which Samson did superbly to claw away.
St Mirren responded quickly and Teale linked with Thompson who saw his effort blocked by Gary Warren.
Reguero was called into action for the first time when he parried Kenny McLean's low drive away for a corner and the hosts should have profited from the resulting set-piece as Marc McAusland leapt unmarked to head Teale's delivery wide.
McAusland again failed to find the target from McGowan's corner five minutes later, however the home fans did not have to wait long for the opening goal, McGowan cleverly chipped the ball through to Goncalves and he composed himself before slotting the ball beyond Reguero.
The confidence was flowing through the home side and Reguero was relieved to see Daniel Devine clear after he had failed to deal with Teale's low cross.
The home supporters roared for a penalty when Graeme Shinnie appeared to fell Goncalves inside the area, however referee Alan Muir quickly waved play-on.
Inverness had a penalty shout of their own with two minutes remaining in the first half as Foran toppled under the attention of Newton and this time Muir pointed at the spot.
McKay stepped up to take the kick and sent Samson the wrong way to level the scores.
Lennon made a half-time substitution as Lee Mair replaced McAusland.
The first chance of the second half fell to the visitors and Andrew Shinnie's shot clipped the top of Goodwin's head before looping over the bar.
Suddenly it was Terry Butcher's side who were enjoying the majority of the possession and Saints reacted by introducing Lewis Guy in place of the tiring Goncalves.
Lennon made his final change when John McGinn came on for Kenny McLean.
It was Caley who continued to look the more likely to grab the next goal and Foran passed up a good opportunity when he shot straight at Samson following McKay's cut-back.
Carey floated a shot just wide of the target as St Mirren created a rare second-half opportunity and they were to go one better just a minute later.
Teale swung over an inch-perfect cross and Thompson's header sneaked into the net after hitting the inside of the post.
Newton almost added a third with a fizzing strike that Reguero did well to keep out and again the home team had regained the momentum.
Andrew Shinnie picked up the first yellow card of the match and Butcher threw on Nick Ross and Philip Roberts for the closing minutes, however it was not enough to earn his side a share of the points.
- Sports & Recreation
- Steven Thompson
- Gary Teale
- Danny Lennon