Kilmarnock 1-3 St Mirren
St Mirren ended a run of seven games without a win thanks to goals against Kilmarnock from two players likely to exit Paisley this summer.
John McGinn had powered a beautiful volley past Cammy Bell to give the Buddies a 20th-minute lead.
That advantage only lasted five minutes, though, with Kris Boyd poking the ball beyond Craig Samson.
But Paul McGowan scored with a 75th-minute penalty and Conor Newton weaved his way in for the third.
A deserved win for the Buddies, their first over Killie this season, ended the home side's hopes of a seventh-place finish, which they could have secured had other results also gone their way.
With more than half of St Mirren's starting line-up destined to leave the Paisley club in the coming weeks, six Buddies had an added incentive to end the season on a high and it was perhaps fitting that two of them should score.
Paul Dummett, the on-loan Newcastle United defender, did not do much for his hopes of impressing any watching scouts when he dallied on the ball, was robbed by Cillian Sheridan and Borja Perez's cross to the back post just evaded the unmarked Chris Johnston at the back post.
The opposite was the case for Dummett's fellow Magpie, Conor Newton, moments later when the midfielder's lovely cross to the back post was thrust into the roof of the net via McGinn's superbly controlled volley.
It was a moment that breathed much-needed life into an encounter that, until then, had all the hallmarks of an end-of-season affair.
The lead would not last long and Borja, who has just signed a contract extending his stay in Ayrshire, slipped the ball through to Boyd.
The Scotland striker, who will almost certainly be looking for a bigger pay cheque this summer after his brief return to the blue and white stripes, neatly tucked the ball beyond Samson, the goalkeeper who could end up at Killie after rejecting a new St Mirren contract.
McGowan, another who has turned down a new deal in Paisley, was next to play his part, cleverly setting up David van Zanten for a shot into the side-netting then firing just over the crossbar from long range.
Newton shot just over the crossbar after a powerful run into the penalty box as St Mirren dominated possession after the break.
However, a young Killie defence handled the pressure with aplomb beyond their tender years - until the second goal that is.
Ashcroft, the 19-year-old who signed a new contract in midweek, had prevented veteran Sam Parkin from marking the end of his Buddies stay with a goal while on-loan Rio Ave striker Esmael Goncalves was substituted midway through the second half.
It was an interception by his replacement, Anton Brady, that led to McGowan's penalty.
Referee Willie Collum pointed to the spot after Ashcroft stretched to tackle the 19-year-old debutant and McGowan fired past Rangers-bound goalkeeper Cammy Bell.
Newton sealed the victory when he jinked into the penalty box and squeezed a shot under Bell before supplying another cross that should have made the victory margin even more emphatic had another of several young debutants, Mo Yaqub, not half-volleyed over from six yards.