Saints' hopes of avoiding the play-offs were dealt a massive blow as they lost to Kilmarnock at The SMiSA Stadium.
The visitors took an early lead when Miguel Freckleton's attempt to stop Tom Lowery's cross reaching Joe Hugill sent the ball towards goal, with Conor McMenamin unable to prevent it crossing the line. The Buddies should have equalised towards the end of a frustrating first half but skipper Mark O'Hara was denied by visiting goalie Max Stryjek.
Things went from bad to worse within 30 seconds of hostilities being resumed, Findlay Curtis pouncing on some slack play to double Killie's lead. There was little by way of a Saints response and Curtis doubled his tally midway through the half to wrap up all three points for the Ayrshire side.
Marcus Fraser made his first Saints appearance since breaking his collarbone against Partick Thistle in the Scottish Cup in March. He was joined in defence by Liam Donnelly, with Conor McMenamin the other change to the side which lost in Dundee last week. Jayden Richardson, Scott Tanser and Richard King were the trio dropping to the bench. There was one change for Killie as Dominic Thompson replaced Bruce Anderson. Greg Kiltie started, with fellow ex-Saint Kyle Magennis on the bench.
Saints made a bright start but it was the visitors who took the lead with their first attack of note. Tom Lowery flighted the ball to the back post for Joe Hugill and Miguel Freckleton's attempt to cut it out inadvertently diverted it towards goal, McMenamin on the line unable to keep it out. Despite a VAR check for handball the goal stood and, to make things worse, McMenamin had picked up an injury and had to be replaced by Tanser.
The Buddies struggled to recover from that setback, much to the frustration of the home crowd. Some trickery from Roland Idowu on the left allowed him to fire in a cross-come-shot that Max Stryjek was unable to hold but it was a brief glimmer of light in a disappointing first half. Killie threatened again on the counter when a Saints attack broke down after ref Don Robertson got in Idowu's way, Kiltie crossing for Lowery whose header drew a fine save from Ross Sinclair, although the flag then went up for offside.
Saints should have been level five minutes before the break, Tanser delivering a trademark cross that the unmarked Mark O'Hara met on the volley but Stryjek blocked with his legs. Allan Campbell then had a shot deflected, the hosts finally coming to life as the half came to a close.
Jake Young and Jayden Richardson replaced Campbell and O'Hara at the break, but within seconds of the restart Saints lost possession and the alert Findlay Curtis pounced to slot past Sinclair to double the visitors' advantage. The hosts should have cut the deficit a few minutes later when the ball broke to Killian Phillips but he sent it wide, his claims he'd been fouled falling on deaf ears.
Killie looked by far the more threatening side and sub David Watson should have done better than head straight at Sinclair. With Saints committing bodies forward they were looking increasingly vulnerable on the break, with Hugill able to charge forward and get in a shot that Freckleton deflected over the bar, Aaron Tshibola not far away from the resultant corner. Curtis then passed up a great chance at the back post but soon made amends when he slammed home the third to put the game beyond doubt.
Youngster Luke Douglas was handed his debut with 15 minutes left and almost managed a goal, but as the game entered the last 10 minutes Killie nearly added a fourth, only a last gasp clearance from Donnelly stopping Tshibola finding the net and adding insult to injury.
Full-Time: St Mirren 0-3 Kilmarnock
St Mirren: Sinclair, Fraser, Donnelly, Freckleton, O'Hara (c) (Young 46), Phillips, Devaney, Campbell (Richardson 46), McMenamin (Tanser 14, King 69), Idowu (Douglas 74), Mandron
Subs: Tamosevicius, Duff, Falconer, Calvin
Kilmarnock: Stryjek, Schjonning-Larsen (Mayo 54), Stanger, Deas (c), Thompson, Lowery, Tshibola, Kiltie (McKenzie 79), Curtis (Magennis 87), Clescenco (Watson 46), Hugill (Anderson 79)
Subs: Wright, Williams, Watkins, Polworth
Referee: Don Robertson
AR1: Calum Spence
AR2: Chris Rae
Fourth Official: Lloyd Wilson
VAR: Andrew Dallas
