Aberdeen will end the season without registering a Scottish Premier League win over Kilmarnock as the teams drew for a third time in this campaign.
Killie's James Fowler snatched at a shot midway through the first half when he should have scored.
And they were made to pay when Jamie Masson, 19, smashed in his first Dons goal before team-mates Josh Magennis and Rory Fallon wasted chances.
Killie kept at it, though, and Dean Shiels fired home in 53 minutes.
Pride, players' bonus money and a greater payment from the Scottish Premier League for a higher final league placing were the rewards on offer at Rugby Park.
And it was Kilmarnock who started the brighter without truly threatening to force an early opener.
Kilmarnock and Aberdeen made three changes each, with Dieter van Tornhout, Danny Racchi and Ryan O'Leary warming the home bench to make way for William Gros, Lee Johnston and Mo Sissoko.
The Dons had Jason Brown back in goal, with Jamie Langfield dropping to the bench, with Rory McArdle and Rory Fallon also starting in place of Russell Anderson and Fraser Fyvie.
Killie had already beaten Aberdeen this season but it was the visitors who gradually took charge of the match.
Dons midfielder Kari Arnason sliced a shot wide and Fallon was just as profligate when, off balance, he tried to chip Cammy Bell from 25 yards.
Killie ought to have taken the lead when Gary Harkins passed to Ben Gordon and he picked out Fowler in the box, but the versatile Killie defender hit a meek shot at Brown instead of taking a touch and picking his spot.
That proved to be a costly miss when Masson, at the back post, finished off a move in which Fallon and Vernon had both attempted to convert Magennis's cross before the ball fell for the youngster to smash the ball home.
Shiels was a frustrated figure when referee Brian Colvin waved away his appeal for a penalty after he had been challenged by Andrew Considine.
At the other end, Magennis came within the width of a post from doubling the Dons' lead when he smacked a left-foot shot off the upright with Bell beaten.
And Fallon should have headed home Ryan Jack's corner instead of nodding the ball into Bell's arms.
Killie levelled seven minutes after the restart, Shiels taking William Gros's pass in his stride and slotting past the despairing Brown.
With 20 minutes remaining, Gros pinged a shot at that Brown managed to smother after it bobbled in front of goal.
Aberdeen tried to reassert themselves with their youthful side as 17-year-old Declan McManus took over from Fallon and teenager Ryan Fraser replaced Masson.
Icelandic midfielder Arnason had a powerful shot saved by Bell and McManus missed the target from right in front of goal as the Dons wasted the chance to take all three points.