Motherwell made one change from the team that defeated Formartine in the Scottish Cup the previous weekend, with Ricki Lamie coming in for Tyler Magloire.

St Mirren were also forced into one switch from the side that progressed to the fourth round by beating Accies. Jon Obika failed a late fitness test with Ryan Flynn coming in to replace him, leaving the visitors one short on the bench.

It was the home side who threatened first as Nathan McGinley swung over a cross from the left and Cole headed just wide from a good position.

St Mirren responded with a chance of their own, Conor McCarthy unable to keep his header under the bar.

McGrath then should have put the visitors in front. Lee Erwin's cushioned volley sent the Irishman in on goal but his shot was weak and easily saved.

Ilkay Durmus then sent a 25-yard free-kick just off target as St Mirren pushed for an opener.

Motherwell then had a great chance of their own. Cole played in Chris Long but Jak Alnwick came out to narrow the angle and made a great save.

St Mirren then had two penalty claims in the space of four minutes.

Durmus' cross struck Robbie Crawford on the arm but referee Kevin Clancy waved it away. Clancy did, however, award a penalty to the visitors shortly afterwards when Stephen O'Donnell caught Dylan Connolly on the corner of the Motherwell box – but McGrath missed for the first time this season after eight successful attempts.

St Mirren had one final chance before the half was out, Erwin pulling Marcus Fraser's long diagonal ball out the air before Kelly denied him with a smart save.

Motherwell forward Jordan Roberts was stretchered off early in the second half after an accidental collision with Fraser.

The home side went in front after 62 minutes. Long's shot was saved by Alnwick but rebounded against Cole, who was standing in front of goal, and across the line.

Allan Campbell could have extended Motherwell's lead only for the goalkeeper to deny him, before Cammy MacPherson's header drifted just wide at the other end.