THE unfathomable disparity between St Mirren’s league and cup form this season goes on. In despatching Welsh Premier League side The New Saints (TNS) to reach the Irn-Bru Cup final, they recorded their 10th victory in 11 cup ties this season. In the Championship they have won just two of 23.

There was an element of Jekyll and Hyde about their performance here, too. With his side desperately poor in the first half and trailing to a Ryan Brobbel goal, manager Jack Ross sent on Lewis Morgan at the break and St Mirren were a side revitalised, running in four goals despite missing a penalty.

TNS, who had former Motherwell and Ross County defender Steven Saunders sent off for a wild challenge on Stephen McGinn, capitulated.

St Mirren now take on Dundee United in the final on either March 25 or 26, an apt reunion on the 30th anniversary of the sides’ meeting in the 1987 Scottish Cup final.

Ross’s side were as good in the second half as they had been poor in the first. Morgan’s introduction made a notable difference and on the hour mark his side drew level. It was a terrific strike from McGinn as he accepted a lateral pass from Stelios Demetriou, advanced forward a couple of strides before unleashing a shot that sailed into the top corner.

Saunders’ red card four minutes later put the Welsh club up against it and St Mirren made them pay from the resultant free-kick, Stephen Mallan bending his shot beyond the wall and into the far corner.

St Mirren were by now fully in their stride and should have scored a third after 78 minutes. Morgan’s cross into the box was stopped only by the hand of Scott Quigley and referee Keith Kennedy gave the penalty. John Sutton, though, could not take advantage, his kick easily saved by goalkeeper Paul Harrison.

Sutton would make amends, however, just a minute later as St Mirren went immediately back on the attack. Stelios fed Kyle Magennis, who sidestepped a tackle before showing great composure to pick out the lurking Sutton who finished well.

All fight had gone out of TNS and they conceded a weak fourth in the final minute, a short free kick from Mallan finding Rory Loy who drilled a low shot beyond Harrison to complete a positive afternoon for St Mirren. It was the cup after all.