Ayr United's early implosion handed Killie the latest derby bragging rights on a remarkable night in Ayrshire.
Derek McInnes' side forged three ahead inside 16 minutes as The Honest Men giftwrapped the points at Somerset Park.
The victory sends Killie back top of the Championship for the first time since December 3 - and ensured quick revenge for Ayr's 2-1 win at Rugby Park last month.
United had stuck with the same side which thrashed Raith last week, while Killie made two changes from their win over Hamilton, with Kyle Lafferty and Chris Stokes returning.
A cracking derby atmosphere welcomed both sides as the game got underway at a frantic pace and it was Killie who got off to a third minute flyer.
United's defence was badly caught out as Fraser Murray ghosted through the middle and slipped in Rory McKenzie to ram home a low finish.
And no sooner had Ayr fallen behind than the game was unravelling for them as Killie bagged a second.
More awful defending saw a Murray corner flicked on by Kyle Lafferty at the nearpost and Oli Shaw arrived unmarked to tap home from two yards.
And incredibly, Ayr were three down in just 16 minutes when another Murray corner was headed home by Jack Sanders with barely a challenge in sight.
A furious Lee Bullen had seen enough and hooked Mark McKenzie and James Maxwell with the game just 20 minutes old and he switched to a back three with Markus Fjortoft and Ben Dempsey were pitched into action.
And Fjortoft almost pulled one back for Ayr with a drive which tested Zach Hemmings, which the keeper did well to tip over the bar.
But then came a moment of madness from the Ayr sub as, only 10 minutes after coming on the park, he saw straight red for hauling down Shaw when clean through on goal.
For United it was then a case of damage limitation but they gave themselves faint hope of a comeback before the break when Kerr McInroy slammed home from the edge of the box after taking a pass from Tomi Adeloye.
Bullen made a third change at the interval, pulling Adeloye in favour of Jack Baird as Ayr went to a back three.
And United refused to buckle despite their numerical disadvantage as they took the game to the visitors at every opportunity.
But Killie were always a threat on the break and Shaw should have played in Lafferty just after the hour for what surely would have been a killer fourth.
Ayr were desperately searching for some kind of inspiration to get back in the contest and sent on teenage striker Fraser Bryden in place of Jordan Houston with a quarter of the game to go.
Killie were able to withdraw Lafferty following his shift with more than 20 minutes remaining as McInnes sought to close the game out.
And they saw it out for a big three points as Ayr were left to reflect on the start that blew their chances.
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