The visitors went ahead in the 12th minute when Ryan Taylor's speculative 25-yard effort took a wicked deflection off Scott Dann, but Rovers dominated the rest of the first half, with Danny Simpson clearing off the line and Leon Best heading against his own bar before David Dunn saw his penalty saved by Tim Krul.
The second half was a quieter affair but Anthony Modeste, Dann and Mauro Formica all missed good chances to earn Rovers what would have been a deserved share of the spoils before Gabriel Obertan rubbed salt into the wound with a late second.
There was still no Christopher Samba for Blackburn, the captain having been out of the side since his transfer request was turned down, but new signing Modeste did make his full debut while Fabricio Coloccini was back for Newcastle after injury.
Rovers had shown encouraging form of late, picking up eight points from their previous five games, but Newcastle dominated the early possession and took the lead in the 12th minute, albeit with a huge slice of luck.
A mix-up between Radosav Petrovic and Dann let in the visitors but Taylor's shot was speculative at best before it took a wicked deflection off the defender, leaving Paul Robinson helpless.
Rovers reacted well and were almost level immediately but Gael Givet's volley from Morten Gamst Pedersen's corner was cleared off the line by Simpson and the defender poked the rebound wide.
Modeste, a loan signing from Bordeaux, then beat the offside trap but Coloccini did well to get back and block his cross, with Petrovic volleying just wide after Newcastle struggled to clear their lines.
Rovers were certainly looking the brighter side now and Krul was nowhere near a curling Junior Hoilett shot that just missed the far post while Coloccini produced another timely block to deny Modeste.
The Argentinian was then penalised for bringing down Hoilett on the edge of the box - a decision that infuriated Newcastle, who felt the winger had dived.
Taylor was booked for confronting Hoilett in the heated aftermath but Coloccini escaped further punishment despite arguably being the last man. Pedersen could not take advantage of the situation, though, seeing his free-kick deflected wide.
Newcastle's luck continued to hold in the 38th minute as Best headed a Pedersen corner against his own crossbar while a mix-up between Krul and Mike Williamson presented Modeste with an open goal from 35 yards but he fired way over.
Rovers at last saw something go their way two minutes before the break when referee Phil Dowd awarded a penalty after Simpson barged into Modeste. But Dunn's spot-kick was weak and easily saved by Krul, who also stopped Givet's tame follow-up.
Blackburn failed to find the same fluency after half-time and were relying mostly on long balls. Steve Kean attempted to inject a bit more creativity by replacing Petrovic with Formica, and they created a glorious chance with 67 minutes gone.
Pedersen released Modeste with a lovely ball but the striker showed a lack of composure in rushing his shot and screwed it well wide with only Krul to beat.
It was at least a glimmer for the Blackburn fans to cheer and moments later Dann headed Pedersen's free-kick straight at Krul from close range.
Rovers fans were celebrating with 10 minutes to go when Martin Olsson's deflected shot fell into the path of Formica, but they then realised the Argentinian had in fact fired into the side netting.
Blackburn were throwing everything at Newcastle and James Perch produced a great block to keep out a Givet shot after Krul had flapped at a corner while Modeste's well-struck volley was straight at the keeper.
But their hopes were ended in injury time when substitute Obertan ended a quick break with the sort of clinical finish Rovers had been so sorely lacking.