The visitors surprised their hosts by taking an early lead through Jamie Hamill before Rangers drew level thanks to top scorer Kris Boyd.
A Kenny Miller double in the space of three first-half minutes ensured maximum points for the Ibrox team.
It was a slow start by Rangers although they were twice denied by Alan Combe in the Killie goal.
The visitors took a shock lead when a mix-up between Madjid Bougherra and Kirk Broadfoot allowed Garry Hay to fire in a cross which Hamill blasted home from close range.
Rangers' equaliser came from a Pedro Mendes corner which found Bougherra at the back post and from his header Boyd forced the ball home.
Rangers went ahead when Boyd's clever flick allowed Miller to outpace Fraser Wright before sliding his shot home.
A clever reverse pass by Mendes which beat the offside trap led to Rangers' third as Miller slid his shot under Combe.
It nearly got worse for Kilmarnock when Combe dropped a Mendes corner but David Weir's shot was cleared off the line.
At the start of the second half Rangers keeper Allan McGregor was at full stretch to save Hamill's powerful shot.
Mendes found Sasa Papac with an outrageous back-heel and, from the return ball, the Portuguese midfielder was only denied a goal by a fine save from Combe.
It took a great tackle by David Lilley to stop substitute Kyle Lafferty as he raced into the box.
In the closing minutes McGregor did well to block a Manuel Pascali shot while, at the other end, Miller should have got his hat-trick but delayed too long after Steven Davis' pass had put him through.