Alex Samuel came off the bench to grab a last-minute equaliser as Morton and St Mirren drew 1-1 in Paisley on Friday night.
Defender Jack Baird headed Saints in front early on when Grant Adam failed to gather a cross but the visitors' pressure paid off when Samuel swept the ball home after Jamie Langfield had parried a Denny Johnstone shot.
The result moves Morton two points clear of Raith Rovers in fourth place while St Mirren climb above Livingston and into seventh spot but Ian Murray's men remain without a home league win.