A Rob Earnshaw hat-trick earned Cardiff an emphatic win after QPR dominated the first half.
The young Welsh international bungled home his first strike after Rangers failed to clear a corner but there was no denying the brilliance of his left-foot strike from 18 yards which buried any hopes QPR still nurtured.
Yet it could have been so different. Calum Willock came closest to breaking the deadlock with two headers which brought the best out of Neil Alexander.
The City keeper dived full length to palm away Willock's effort after two minutes. He then scampered across his goal to keep out a glancing header from the on-loan forward who got the faintest of touches to a Tommy Williams free-kick.
Kevin Gallen also missed out on two first-half chances, his first was a spectacular chip over a defender before half-volleying just over the bar. The second came as he latched on to a back header from Brett Angell, but although Gallen had a better angle he only hit his low drive straight at the keeper.
Richard Langley was the last in the first half to test Alexander with a long-range effort which still required the keeper to turn the ball around the post.
In between Cardiff's large army of fans only had an Earnshaw cross which Andy Legg hammered into the sidenetting to cheer.
However the shape of things to come appeared on 49 minutes, when the speedy Earnshaw was only denied by an even quicker Simon Royce as they both chased a Cardiff throughball.
After Earnshaw's double whammy, the fire went out of the game but Williams' drive from 20 yards may have had pace but still only needed a regulation save.
With six minutes to go Alexander should have been beaten at last as the two Rangers subs combined. Dennis Oli's header fell into the path of the unmarked Paul Furlong who thrashed his shot high and wide.
There was just time for Earnshaw to collect the match ball when he latched on to a poor Terrell Forbes backpass and dinked it over the stranded keeper.
Insult for Rangers fans was added to injury when Williams also repeated a dreadful attempt at finding Royce only for Andy Campbell to make it four after the keeper had parried the first attempt