Ross County 1-2 St Mirren

• Martin Woods opens scoring with penalty

• Stephen Mallan equalises before half-time

• Mark Brown sent off late on

• Steven Thompson scores winning penalty

• Ross County three points clear of Motherwell

Steven Thompson's last-minute penalty earned relegated St Mirren a win that throws open the race to avoid the play-offs.

County went ahead when Liam Boyce was tripped in the box and Martin Woods scored from the penalty spot.

Stephen Mallan fired Saints level with a deflected shot from distance.

And Mark Brown was sent off for fouling Lewis Morgan before Thompson scored low into the corner. It leaves County three points ahead of Motherwell, in 11th.

It was a result few observers would have predicted but St Mirren deserve real credit for a resilient display following confirmation of their relegation on Friday night, when Motherwell beat Kilmarnock.

Boyce went close after making something of deliveries from Marcus Fraser, but failed to hit the target, and Woods was first to test Mark Ridgers in goal after a free-kick.

County's Tony Dingwall tested the keeper from distance before the breakthrough arrived. A swift turn in the box by Liam Boyce brought a foul by Sean Kelly.

And Woods superbly fired the ball high into the top corner from the penalty spot.

Steven Thompson scored from the penalty spot past 'makeshift' keeper Darvydas Sernas

A minute later County should have gone further ahead. Boyce drilled a ball across the six-yard box, Craig Curran connected strongly but Jason Naismith produced a wonderful sliding challenge to divert the danger.

Boyce failed to hit the target when he really should have, and what followed shocked the entire stadium and turned this game into an intriguing contest.

With the ball at his feet in a central area, Mallon struck a fierce shot that deflected off the stooping Scott Boyd and looped away from Brown into the corner of the goal.

Ross County seemed reinvigorated after half-time and created chance after chance as they tried to move closer to retaining their Premiership safety.

Dingwall fired narrowly wide then Jackson Irvine's header connected with a defender, but appeals for a penalty were swiftly rebuffed by referee Steven Maclean.

Irvine became increasingly threatening from set pieces in particular, the midfielder narrowly sending two headers over the bar.

Woods, Dingwall and Michael Gardyne threatened more and it seemed inevitable that County would be rewarded.

The game ended in a dramatic way. Substitute Morgan outpaced Marcus Fraser and as he broke into the box he was caught by goalkeeper Brown, who was red-carded.

County had already used their three substitutes and one of those, striker Darvydas Sernas, put on the keeper's gloves as Thompson expertly rolled the ball into the corner from the penalty spot.

It leaves the Dingwall side perilously close to a play-off with two vitally important games to follow.