Two eye-catching goals from Mark Roberts and Ally Mitchell in the second half of an exhilarating contest stretched Killie's unbeaten run to nine games and kept them on Rangers' tail.
Celtic? They are seven points off the pace, and to complete an off day, Stephane Mahe was dismissed in the 89th minute for his second caution to add to the problems of the beleaguered Josef Venglos.
When second meets third, the occasion can often be more about fear than ambition. Rugby Park though, was fortunate to see that nervousness of dropping further behind Rangers translated into a hectic but enterprising opening The pace rarely dropped below frenetic, as the teams swapped chances with rapidity.
Jerome Vareille seemed certain to give Kilmarnock the lead after just five minutes when he controlled Gary Holt's clever pass with his chest but swept his shot wide. Then Martin Baker squandered a wonderful opportunity after Ian Durrant had delivered a measured pass into the full-back's stride, but Baker's low shot sneaked the wrong side of the post as it sped across the goalmouth.
Craig Burley and Simon Donnelly provided a response for Celtic, peppering Gordon Marshall's goal and bringing saves out of the Kilmarnock goalkeeper.
Burley, though, did not last much longer. The Scotland midfielder limped off in the 22nd minute with a strain, as the undiluted desire emerged in the shape of hard, brutish play that saw Celtic's Tom Boyd and Paul Lambert booked.
Henrik Larsson should have provided the goal the game needed in the 35th minute when he raced clear on to Donnelly's fine pass but shot wide.
The deadlock was finally broken by the home side in the 54th minute when Roberts illustrated why he was preferred in attack to Paul Wright and Ally McCoist. Mitchell was the creator, hitting the goal-line and swinging over a fine cross for Roberts to rise and glance a header past Jonathan Gould.
Roberts almost added a second 11 minutes later before Mitchell metamorphosed from creator into executor in the 70th minute. Durrant's free-kick was not cleared by the Celtic defence, and Holt set up Mitchell to bury an 18-yard shot past Gould.Reuse content