The home side could have gone ahead in the opening stages of the match when Scott Agnew was allowed space and time inside the box, but could only slice his strike past the post.
The visitors responded when Stefan McCluskey raided down the flank and cut back onto his right foot. The forward angled a shot towards the top corner that sailed inches over the bar.
In the second half, Calum Gallagher tested the handling ability of Adam with a strike from long range, but the keeper was able to make the stop on the ground.
St Mirren could have notched their second goal when Stephen Mallan whipped a free kick into the box, but Andy Webster could only guide his header over the bar.
Michael Tidser should have brought the home side level, but he could only drill his right-footed strike wide of the post after being well placed in the penalty area.
The visitors pressed for an equaliser late in the game and were rewarded when Samuel managed to bundle home an effort from close range to earn his side a share of the spoils.