Match ends, St. Mirren 4, Kilmarnock 1.
Bottom side St Mirren moved to within seven points of Motherwell with four games to go by beating Kilmarnock.
Buddies defender Sean Kelly drilled into the far corner and Kieran Sadlier's close-range header doubled the lead.
Josh Magennis pulled one back from 18 yards for Kilmarnock.
But an Alexei Eremenko handball and a Manuel Pascali foul gave St Mirren two penalties which captain Steven Thompson duly converted.
Suddenly there is a chink of light for Gary Teale's St Mirren as they stare up out of the automatic relegation trap door that most felt had already shut and locked.
With 12 points still up for grabs, the Buddies know they can apply further pressure on Motherwell, who visit Paisley in the penultimate round of fixtures.
St Mirren Park has not previously been a daunting place to come calling - this was only the hosts' second home league win of the season - but Teale's side seemed re-energised against an underwhelming Kilmarnock.
The 50th anniversary of Killie's only top-flight title win should have inspired them, but instead Gary Locke's side struggled in the first half and St Mirren capitalised.
Centre-back Kelly was still up front following a set piece when Nathan Eccleston's misplaced pass presented the Buddies youngster with the chance to drill the ball into Craig Samson's far corner for his third of the season.
A last-ditch challenge on Thompson by Kilmarnock defender Lee Ashcroft did not bring a penalty but St Mirren's second came soon after when former West Ham forward Sadlier picked up the scraps when Jason Naismith's shot was partially saved.
Magennis's sixth of the season gave Killie a lifeline - the Northern Irishman finishing well beyond Mark Ridgers after Chris Johnston's pass.
Any resurgence would be short-lived though as referee Kevin Clancy awarded St Mirren the first of two penalties when Stephen Mallan's free-kick struck the hand of Eremenko.
Thompson's execution was not the cleanest but he saved a nicer finish for his second penalty eight minutes later after Pascali had felled Dayton.
Both sides hit the woodwork late on - Magennis and Mallan coming close - and Thompson got a standing ovation when substituted.
- 14ReillySubstituted forCuddihyat 87'minutes
- 17DaytonSubstituted forBrownat 76'minutes
- 10SadlierBooked at 82mins
- 9ThompsonSubstituted forGowat 79'minutes
- 26O'HaraBooked at 56mins
- 29PascaliBooked at 64mins
- 19SlaterSubstituted forEremenkoat 45'minutesBooked at 59mins
- 16ObadeyiSubstituted forMcKenzieat 70'minutes
- 14EcclestonSubstituted forMillerat 27'minutes
- Kevin Clancy
- Shots on Target
Second Half ends, St. Mirren 4, Kilmarnock 1.
Attempt missed. Mark O'Hara (Kilmarnock) right footed shot from outside the box is close, but misses to the right.
Stephen Mallan (St. Mirren) hits the bar with a right footed shot from outside the box.
Hand ball by Craig Samson (Kilmarnock).
Attempt saved. Lee Miller (Kilmarnock) right footed shot from the centre of the box is saved in the bottom right corner.
Foul by Barry Cuddihy (St. Mirren).
Rory McKenzie (Kilmarnock) wins a free kick in the attacking half.
Attempt saved. Adam Brown (St. Mirren) left footed shot from the centre of the box is saved in the centre of the goal.
Stephen Mallan (St. Mirren) wins a free kick in the defensive half.
Foul by Rory McKenzie (Kilmarnock).
Substitution, St. Mirren. Barry Cuddihy replaces Thomas Reilly.
Attempt blocked. Chris Johnston (Kilmarnock) right footed shot from outside the box is blocked.
Corner, St. Mirren. Conceded by Mark O'Hara.
Corner, St. Mirren. Conceded by Manuel Pascali.
Stephen Mallan (St. Mirren) is shown the yellow card.
Attempt saved. Josh Magennis (Kilmarnock) header from the centre of the box is saved in the bottom right corner.
Josh Magennis (Kilmarnock) hits the left post with a header from the centre of the box.
Corner, Kilmarnock. Conceded by Kieran Sadlier.
Corner, Kilmarnock. Conceded by Jack Baird.