Ross County dropped into the relegation play-off spot after squandering a leading position to go down 3-1 against St Mirren.
Jordan White had given John Hughes’ men a first-half lead, however goals after the break from former Staggies attacker Lee Erwin, Ilkay Durmus and Jamie McGrath secured the victory for the Buddies.
With Kilmarnock defeating Dundee United, County now drop to second bottom with three matches remaining, meaning their survival fate is now outwith their own hands.
County made just one change from the side which drew 2-2 with Kilmarnock in their last outing, with Leo Hjelde drafted in to replace Carl Tremarco.
St Mirren threatened within the opening 90 seconds, with Jay Henderson seeing an effort blocked behind.
It was a slow start from both sides, however the Staggies took the lead with their first clear-cut opportunity. Iain Vigurs picked out Billy Mckay with a quick free-kick, with the attacker’s low delivery partially cut out by the Saints defence.
The ball was quickly returned into the box by the head of Jordan Tillson, which set up White to lash high past Jak Alnwick with an instinctive finish.
County pushed for a second goal before the break, with Michael Gardyne denied from long-range by Alnwick, while Mckay was unable to get a connection on a Jason Naismith delivery.
Saints were close to a leveller on 39 minutes when Henderson’s cross set up Kristian Dennis, whose headed was well saved by the outstretched Ross Laidlaw.
County were close to adding a second just before the interval, with Alnwick doing well to tip over an excellent Tillson effort which looked destined for the top corner.
It proved a crucial save, as Saints levelled five minutes after the break courtesy of former Staggies attacker Erwin, who guided a header past Laidlaw after meeting Richard Tait’s cross.
The Buddies were denied a second by Laidlaw on the hour mark, with the goalkeeper doing well to block Conor McCarthy’s close-range effort following a Durmus corner.
County pushed to regain the lead, with Naismith seeing a header cleared off the line after getting on the end of a Gardyne corner.
Saints turned the game on its head on 71 minutes though, with Colln Quaner setting up Durmus to tuck home from just inside the box with a neat first-time finish.
The Buddies netted a clinching third goal deep into stoppage time, with McGrath tucking home from the spot after Hjelde was penalised for handball.