Troubled Ayr put their cash problems aside to defeat title favourites Morton at Somerset Park.
The Honest Men face massive debts and the threat of administration, but showed little sign of worry as they turned on a show for new boss Mark Shanks.
Both sides had chances in an open first half, and Ayr's Craig Conway was unlucky to see his left-foot drive crash off the post.
Morton were restricted to long-range efforts with John Maisano and Stewart Greacen both firing over.
Ayr turned the screw in the second half and took the lead when Stewart Kean was played in by Graeme Brown and fired home from 12 yards.
Kean saw an identical chance rebound off the post only moments later as Ayr took control.
Morton almost found the route back when Chris Miller fired a long range shot off the bar before Ayr sealed it.
Darren Henderson played a ball over the top for Kean to run on and fire into the top corner with 16 minutes remaining.