The winning goal for the visitors came with just four minutes to play as Lawless produced some skill on the wing before his deep cross was headed in by Smith at the back post.
That capped an action packed game which had drama right from the off as Higdon hit the post from a corner in the opening minutes. However, it was Morton who took the lead as Graham volleyed beyond Hollis following a set piece.
A beautiful curled effort from Jamie Murphy restored parity before the interval and early in the second half Motherwell went in front as Pollock guided Saunders' cross into the net with the aid of the post. Morton were not done quite yet though and Andy Jackson levelled with 15 minutes remaining as the honours seemed set to be shared.
Smith's timely header ensured that wasn't the case and Stuart McCall can reflect on a job well done by the 21 (yes, twenty-one) players he used in the course of the evening.
A full report can be read on the official site.