Saints made it through to the quarter-finals of the Viaplay Cup with a well-deserved win over Motherwell in Paisley.
The only goal came inside the first 10 minutes and was a screamer, Caolan Boyd-Munce running onto the ball and thundering it into the top corner from a good 20 yards.
Motherwell fought back after the break, Zach Hemming producing a great save from Theo Bair, but the better chances came at the other end with Conor McMenamin and Toyosi Olusanya to getting Saints' second. It never came but it didn't matter as Saints held out to make the last eight.
Stephen Robinson took the "if it ain't broke, don't fix it" approach and stuck with the side that had started the previous week's win over Dundee, with Mikael Mandron leading the attack against his old club. Former Buddie Paul McGinn started for the visitors, who handed Davor Zdravkovski his first start.
The Buddies have been making quick starts to their games this season and did so once more against the Steelmen. As Ryan Strain tried to force his way through the Motherwell defence, the ball wouldn't quite sit up for him on his right foot and eventually trickled away from him. However, it sat up perfectly for Caolan Boyd-Munce, who ran onto it and thumped a tremendous shot into the top corner. It was the midfielder's first goal since his arrival in March and put Saints in front with less than nine minutes on the clock.
Keanu Baccus tried from a similar position midway through the half as the Motherwell defence backed off Saints' World Cup star, who fired just over the bar from distance. The Aussie then had a shot deflected wide as the hosts tried to crank up the pressure against a Motherwell side who hadn't threatened. Their first corner caused a bit of chaos and uncertainty in the Saints box before it was eventually dealt with and when the visitors finally did have a shot, Callum Slattery's ambitious effort was always going high and wide.
Mandron sent a volley trickling wide early in the second half before Saints goalie Zach Hemming was called into action for the first time, producing a superb finger tip save to keep out a great effort from Theo Bair, Dan Casey heading wide from the resultant corner. For the first time the visitors were beginning to ask questions of the Saints rearguard but the Buddies were still capable of causing problems at the other end, Mandron having a shot blocked after he did well to get on the end of Greg Kiltie's pass.
The home side – and some players were screaming for a penalty when Richard Taylor's header from Boyd-Munce's corner seemed to hit a Motherwell arm, however ref Willie Collum was unmoved – and with VAR not in operation the decision stood. McMenamin had a great chance to double Saints' lead when Mandron's flick at the half way line sent him charging towards the 'Well goal, however the visiting defence was able to get back just in time to crowd him out and his shot was blocked. Motherwell could then have been level, Stephen O'Donnell finding Mika Biereth and the sub slid the ball across goal only for it to be just beyond the reach of Conor Wilkinson at the back post.
As the game approached the final 10 minutes, Mandron was booked for barging into the back of Shane Blaney, giving the visitors a free-kick in a dangerous position, however Slattery sent it well over. A couple of minutes from the end Olusanya, who had replaced Boyd-Munce, was sent through on goal only to be pulled back by Bevis Mugabi. The defender escaped with a booking and the free-kick came to nothing. Some neat passing gave Olusanya the chance to finish things in stoppage time but Motherwell keeper Liam Kelly kept out his shot to ensure a tense final few minutes.
Tackles and bodies seemed to be flying everywhere as Saints tried to snuff out the danger, Charles Dunne booked for flattening Biereth and Paul McGinn cautioned for fouling Strain at the same incident. Strain was replaced by James Bolton as Saints tried to tighten up for the free-kick, which was easily dealt with.
In the final minute of added time Olusanya almost finished things off only to see his shot hit the post, Kiltie then putting the rebound over. It didn't matter as Saints were able to comfortably see out what little time remained to make it through to the draw with the quarter-finals.
Full-Time: St Mirren 1-0 Motherwell
St Mirren: Hemming, Fraser (c), Gogic, R.Taylor, Strain (Bolton 90), Baccus, Boyd-Munce (Dunne 82), Tanser, Kiltie, McMenamin (Olusanya 82), Mandron
Subs Not Used: Urminsky, Kenny, Flynn, Lennon, Greive, Nahmani
Motherwell: Kelly, McGinn, Mugabi, Casey, O'Donnell (Ferrie 76), Blaney, Slattery, Spittal, Zdravkovski (Miller 55), Wilkinson (Efford 76), Bair (Biereth 67)
Subs Not Used: Oxborough, Lamie, McGinley, Wilson, Garcia
Referee: William Collum
Assistant Referee: Daniel McFarlane
Assistant Referee: Craig Ferguson
Fourth Official: Lloyd Wilson
Attendance: 5,249