Arnor Sigurdsson scored twice as Blackburn thrashed QPR to increase the pressure on R's boss Gareth Ainsworth.
Tyrhys Dolan and Sammie Szmodics also netted in a thumping away victory for Rovers, who had lost their previous four league matches.
Ainsworth's future as Rangers boss is in doubt after another diabolical performance at Loftus Road, where the west London side have won just once since last October and have lost five of their six home matches so far this season.
The R's are in the bottom three, have gone six games without a win, and look both defensively vulnerable and devoid of attacking ideas.
They almost went down under Ainsworth last season and have so far fully justified being among the favourites for relegation this term.
Blackburn took control of the game by punishing woeful QPR defending to score twice in the space of four minutes midway through the first half.
The opener came on 19 minutes, when Joe Rankin-Costello drifted away from Jack Colback to collect Dilan Markanday's pass and pull the ball back from the right for Dolan to score his first goal of the season.
Rangers were carved open again soon afterwards, with Markanday once more involved in the build-up on the right-hand side.
This time Szmodics was found by Markanday and laid the ball across to Sigurdsson, who got in front of Ziyad Larkeche to apply the finish.
Rangers had made a decent start, with Sinclair Armstrong bringing a near-post save from keeper Leopold Wahlstedt after combining with Ilias Chair, before Wahlstedt gathered Lyndon Dykes' header from Larkeche's right-wing corner.
After finding themselves two down, the hosts tried in vain to reduce the deficit before the interval, with Andre Dozzell seeing a shot saved by Wahlstedt shortly before crossing for Dykes, who headed wide.
Any realistic chance of a Rangers comeback evaporated when Sigurdsson struck again after 59 minutes, collecting Dolan's pass near the left of the penalty area and curling a low shot beyond keeper Asmir Begovic and into the far corner of the net.
Andy Moran should have made it four but missed the target from close range after Begovic had parried Szmodics' shot.
But Szmodics added the fourth in the 66th minute following an error by left-back Larkeche.
Operating as a makeshift right-back in place of the dropped Osman Kakay, Larkeche made a mess of an attempted clearance and presented the ball straight to Szmodics, who calmly slotted past Begovic.
*copy from Press Association.
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