Managerless Livingston won their first away match since March to lift themselves off the foot of the table.
A Jim Hamilton double and a glorious strike from skipper Burton O'Brien was too much for a directionless Killie side.
Peter Leven succumbed to the Curse of the New Contract as the foot injury he picked up after extending his Killie career kept him out of this match, James Fowler being preferred to Eric Joly in midfield.
Gary Wales' recent goalscoring form from the bench and in the reserves saw him take over from Craig Dargo up front.
Livi caretaker manager Alec Cleland rang the changes from the side which went down to Aberdeen, bringing youth team players Stephen Adam, James McPake and Ryan Harding into the starting line-up.
If his young side needed any confidence, they received it in the seventh minute when they took the lead with their first attack. David McNamee drove over a cross from the right which Hamilton met perfectly to nod past Alan Combe.
Kilmarnock were having difficulty adjusting to the tricky underfoot conditions, but gradually found their feet and matched Livi's feat of scoring on their first foray into the opposition box.
Allan Johnston picked up David Lilley's long ball after it had been misjudged by Livi skipper O'Brien and he drove into the area and lifted the ball over Roddy MacKenzie with the aid of a slight deflection.
Killie appeared to have the measure of the league's bottom club, without stretching the keeper and it was a shock to the home fans when Livi went back in front.
Even more shocking was the fact that the goal came from an error by keeper Alan Combe. He tried to catch O'Brien's 30-yarder rather than touch it to safety and the ball squirmed from his grasp into Hamilton's path and he had the simple task of tucking the ball home.
Jim Jefferies introduced Joly at the start of the second half, but soon found his side further behind following a wonderful strike from skipper O'Brien.
He collected the ball from a short corner in the 60th minute and skirted the penalty box before rifling a great left-foot shot high into the net.
It could have been even worse for Jefferies had Freddy Dindeleux not been on hand to head off his own line after Derek Lilley had by-passed Combe with his cross and Hamilton headed goalward.
Gary McDonald almost grabbed a lifeline for Killie, but MacKenzie saved with his feet. Substitute Stevie Murray had a half chance which he volleyed wide in the closing stages, but it was not to be Killie's day.