Saints missed a golden opportunity to finish a difficult year on a high as they failed to hold on to a lead against Renfrewshire rivals Morton.
Gary MacKenzie's header gave the Buddies the lead at the break and their chances of claiming a priceless three points improved when Jamie McDonagh was sent off for stamping on Rocco Quinn early in the second half.
However, after that Saints seemed to get deeper and Morton's pressure paid off in stoppage time as Ricki Lamie bundled the ball home at a corner.
Saints stuck with the same team that lost at Tannadice on Christmas Eve and they had an early penalty appeal turned down when Jason Naismith appeared to be bundled over inside the box by Mark Russell. There was then a lucky escape as MacKenzie had to hack the ball clear with Ross Forbes ready to tap in the opener. Jamie Lindsay was booked for flattening Stevie Mallan soon after before Morton could've taken the lead, Scott Gallacher punching a Forbes corner to Gavin Gunning but the defender volleyed wide.
John Sutton was next to be denied a penalty after appearing to be pushed to the ground after collecting Rocco Quinn's cross. It took midway through the half for the striker to get a sight of goal when he headed wide from Lewis Morgan's cross.
Michael Doyle's header found the top of the net as the visitors threatened again before Saints went even closer, Gary Irvine's cross finding Sutton whose header was tipped over by Derek Gaston. The resultant corner bore fruit as Mallan's superb delivery found MacKenzie in acres of space and his header flew past Gaston to give the Buddies the lead and the big defender his first goal for the club.
Gallacher did well to palm away Russell's shot as the Ton looked for a quick equaliser. Another chance came when Quinn's foul on Jamie McDonagh sent the Morton player sliding into the advertising boards but Forbes' pacey delivery skidded off the head of Thomas O'Ware and behind.
Saints hadn't threatened since taking the lead but Kyle Magennis had half a chance to double the advantage as Quinn slipped the ball to the youngster at the edge of the box, however his effort was a yard or two away from finding the top corner.
As the first half came to a close Morton were unlucky not to equalise when Ricki Lamie headed Forbes' free-kick over the bar before Gallacher blocked Gary Oliver's effort to force home the rebound. Morton felt they should have had a penalty in the aftermath for a challenge on Oliver and the subsequent injuries spelled the end of his afternoon as Kudus Oyenuga replaced him at the break.
Half Time: St Mirren 1-0 Morton
Forbes was booked early in the second half for a bad tackle on Magennis but worse was soon to follow for the visitors. After a free-kick was given for a foul on Quinn by McDonagh, the Morton man appeared to stamp on the Saints midfielder. Ref Nick Walsh quickly sent McDonagh off but there was a short delay while Quinn was treated before being replaced by Lewis McLear. Mallan's attempted lob of Gaston was easily dealt with as the Buddies tried to make their advantage count, however Morton weren't lying down and asked plenty of questions of the home defence.
MacKenzie was denied a second when he saw a header cleared off the line before Naismith and sub David Clarkson both made their way into the book for fouls.
It looked as if the Buddies would hold out but in stoppage time Morton grabbed a leveller. The visitors won a corner which was missed by Gallacher before falling for Lamie to sweep home. It was a frustrating end to the match and the year as Saints look to haul themselves from the foot of the table.
Full Time: St Mirren 1-1 Morton
St Mirren: Gallacher, Naismith, MacKenzie, Webster, Irvine, Quinn (McLear, 61), Magennis (Clarkson, 71), McAllister, (Gallagher, 88) Mallan, Morgan, Sutton
Subs Not Used: Langfield, Baird, Hardie, Shankland
Morton: Gaston, Lamie, O'Ware, Gunning, Doyle, Oliver (Oyenuga, 45), Forbes, Lindsay (Nesbitt, 74), Russell, McDonough, Murdoch (Tidser, 80)
Subs Not Used: McNeil, Kilday, Scullion, Strapp
Referee: Nick Walsh
Assistant Referee: Kylie McMullan
Assistant Referee: Calum Spence
Attendance: 4,902
Match report and gallery pictures © Stephen Smyth