Newcastle picked up their first win of the season with new boss Graeme Souness - who takes over on Monday - watching from the stands.
Garry Flitcroft turned Laurent Robert's corner into his own net for the opener after just nine minutes.
Lee Bowyer was twice denied strong penalty claims in the opening stages before Alan Shearer headed home the second at the far post.
Andy O'Brien made the points safe late on with a neat spin and shot.
Newcastle went into the match fourth bottom of the Premiership table with just two points from four games.
But with Shearer restored to the starting line-up, Newcastle started like a team with a point to prove and felt they should have been awarded a penalty after three minutes.
Dominic Matteo appeared to catch Bowyer, but despite passionate protestations from the Magpies players, referee Dermot Gallagher waved play on.
Blackburn, with Tony Parkes in temporary charge after Souness' decision to quit for Newcastle five days earlier, countered with Dickov forcing Shay Given into action.
But it did not take long for Newcastle to take the lead, with the recalled Flitcroft deflecting the ball into his own net.
Robert, whose in-swinging corner led to the goal, smashed a thunderous free-kick just wide of Rovers' goal.
And Bowyer then had another strong penalty appeal turned down as the home team threatened to take the match beyond Blackburn.
With the visitors stretched by another swift Newcastle attack, the ball broke towards Bowyer just inside the penalty but as he closed in on the ball Morten Gamst Pedersen appeared to trip him.
Shearer appealed to Gallagher but his anger turned to smiles shortly afterwards when he headed Craig Bellamy's cross beyond Friedel for his first goal from open play this season.
The Newcastle skipper proved his worth in defence - and underlined his commitment to the team - shortly afterwards, turning the ball out for a corner as Rovers started to assert themselves on the match.
The lively Brett Emerton drilled a shot narrowly over the Newcastle crossbar and Jon Stead broke down the right but Given held his cross.
Blackburn kept trying to force their way back into the match but, after a spate of early chances, both defences tightened up considerably after the break.
Newcastle finally prised open the Rovers defence with Bellamy playing Bowyer through after a Shearer flick-on, but Friedel made a good save.
And O'Brien sealed a happy afternoon for the home team with a superb goal.
A brilliant turn and spin from Bowyer's drilled pass-cum-shot took the ball past Matteo before O'Brien struck the ball past Friedel.
Newcastle: Given, Carr, O'Brien, Hughes, Elliott,
Dyer (Milner 88), Jenas, Bowyer, Robert (N'Zogbia 90), Shearer, Bellamy (Ameobi 77). Subs Not Used: Kluivert, Harper.
Booked: Bellamy, Ameobi.
Goals: Flitcroft 9 og, Shearer 16, O'Brien 83.
Blackburn: Friedel, Neill, Short, Matteo, Gray,
Emerton (Bothroyd 78), Flitcroft, Ferguson, Pedersen (Douglas 45), Dickov, Stead. Subs Not Used: Tugay, Enckelman, Johansson.
Ref: D Gallagher (Oxfordshire).