The first half was one in which Newcastle were totally dominant; the hosts did not register a single shot.
Mo Diamé came within an inch of opening the scoring as he hammered a strike against the crossbar. It was a magnificent strike by the Senegalese man.
Yoan Gouffran picked out 19-goal-marksman Dwight Gayle with a beautiful disguised pass. Gayle had slipped the defence, but could not find a way past the keeper with his left-footed strike.
Strikes by Matt Ritchie and Isaac Hayden also came close, but Blackburn held firm... just.
Aside from a half chance for Craig Conway, Blackburn did not threaten whatsoever. A deep cross fell at his feet, but he lacked the confidence required to take a shot and was crowded out in the end.
The second half began and Newcastle continued to pile the pressure onto the hosts. Dwight Gayle got his head on the end of the ball and although it found the net, the linesman's flag was up. Ciaran Clark was next to find his celebrations cut short after he was judged to have fouled a Blackburn defender inside the box.
Blackburn came back into it after that. Sam Gallagher, who had replaced the injured Conway, struck a fierce shot just wide of Karl Darlow's left hand post.
Then disaster struck. Jack Colback committed a silly foul on the edge of the box and up stepped Charlie Mulgrew. Of course, just as he did at St James' earlier in the season, he found the net. Blackburn 1-0 Newcastle.
Rafa Benitez threw on Ayoze Perez, Christian Atsu and Daryl Murphy later on, but neither could impact the game.
There was a late chance after Paul Dummett, who was making his 100th appearance for the Magpies, fired low towards goal, causing a hectic goalmouth scramble.
In the end though, Newcastle found themselves defeated once again. With Brighton having come from behind too at Fulham, they are now two clear at the top, having played a game less.
Oh how the tables have turned.