Against the run of play Matt Oakley had put the bottom club ahead after 27 minutes and Paul Jewell's outfit should have doubled their advantage ten minutes later after Ryan Nelsen brought down Kenny Miller.
But Steve Howard's weak penalty was easily saved by Brad Friedel.
Within a minute Rovers had equalised through Roque Santa Cruz with his eighth goal in five games, then just before the break David Bentley, who had an outstanding game, fired home from 25 yards for what proved to be the winning strike.
Blackburn boss Mark Hughes was "delighted" with the win: "We showed great character, great response from us.
"We had a number of a chances, could have finished them off a lot earlier.
"We're delighted with that win. It's been a decent period, the last week or so."
Hughes singled out Bentley for special praise and insisted his form was down to his controversial withdrawal from the England Under-21 squad for last summer's European Championships.
"He's playing exceptionally well at the moment," Hughes said.
"In the summer, we made the decision for the benefit of David that he needed to get some rest.
"Now we're reaping the benefits and David is as well."