A FAR post header from Joe Ledley – courtesy of Mark Kennedy's lob from the byline – was enough to consign Rangers to a fifth home defeat of the season.
The breakaway winner was rough on Neil Warnock's men, who dominated much of proceedings without finding that killer touch in the final third.
Even so, Lee Cook nearly saved the day after coming off the bench late on – volleying Adel Taarabt's near post chip straight at goalkeeper David Marshall from close range.
There was little danger of the fans overdosing on excitement, though, with Rangers having won their cup final at Palace last week to dispel most of their relegation worries and Cardiff all-but in the play-offs.
And the default setting of the match invariably featured a mazy run from Taarabt, followed by a disappointing outcome.
But to be fair to the outrageously gifted Moroccan, he was unlucky to see a first half shot from 20 yards roll across the face of the goal after striking the inside of a post.
And he could hardly be blamed for Hogan Ephraim and Tamas Priskin both making a hash of his fine pull-back from the byline.
Peter Ramage rescued Rangers early in the second half after Radek Cerny spilled a Ross McCormack free-kick with City's Anthony Gerrard ready to pounce.
But that was a rare moment of danger at that end of the pitch until the goal. For all that, the Rs failed to make possession count and long distance shooting was not their forte today.