It took St Mirren less than a minute to threaten when David Proctor's late challenge on Craig Dargo presented the visitors with a free-kick 25 yards out, but Ryan McCay's effort was easily held by Michael Fraser.
It proved to be the only time in the opening period that Fraser was called into any meaningful action as Caley Thistle dominated the remaining 44 minutes of the first half.
Don Cowie blazed over from less than eight yards after being picked out by Dougie Imrie, before Russell Duncan's effort from the edge of the box had to be parried away by Saints goalkeeper Mark Howard.
With half-time fast approaching, Fraser's long punt found Dennis Wyness racing in on goal, but his lobbed effort narrowly bounced past the upright with Howard stranded.
Minutes later, Imrie once more caused problems for the visitors defence, this time finding Marius Niculae unmarked but his low drive struck the foot of the post.
The ball rebounded to Wyness in the six-yard box, but he took too long to get the ball from out from under his feet and this allowed John Potter to make a timely intervention.
Having played second fiddle to Caley Thistle for much of the second half, St Mirren improved after the break with Billy Mehmet fizzing a shot a yard over the crossbar, while Stephen O'Donnell forced Fraser into a smart save at his near post.
Caley Thistle's hopes of finishing the season on a high were then dealt a blow on 53 minutes when Proctor was shown a straight red card for hauling down Dargo when the former Inverness striker appeared to be through on goal.
St Mirren did have two decent chances to win the game late on as Mehmet connected with McCay's cross only to see his low effort blocked by Fraser, while Dargo's shot curled inches past the post.