Two goals from Morten Gamst Pedersen, the second of them a typical curling left-footed free-kick in injury time, rescued 10-man Rovers after United had done enough to deserve a point towards their fight to stay clear of the Premiership's relegation places.
On his second Blackburn debut, David Dunn's one real contribution was to be pulled back by Michael Tonge just outside the area after the end of the 90 minutes. Pedersen, who had put Blackburn ahead once, missed a wonderful chance to give them the lead for the second time, lined up the free-kick and left Paddy Kenny helpless.
"Technically, he's as good as anyone I've seen and I've had the pleasure of playing with and against some of the best," said his manager, Mark Hughes, for whom the free-kick was "unsaveable".
United's understandably disappointed Neil Warnock did not believe it should not have been awarded. "It was a nothing free-kick," he said. "When you've played the game you know whether it was a deliberate pull-back."
Pedersen had given Blackburn the lead in the 22nd minute after Rob Hulse had hit the post for United in the opening stages. Pedersen out-jumped Rob Kozluk for a rare headed goal after Brett Emerton had been allowed by some slack defending to measure his cross from the right.
It was a lead that did not last long. It was two minutes, in fact, before Jon Stead did what forwards are supposed to do to their former employers. Hulse got his head to a Phil Jagielka free-kick and Stead got in front of one of Rovers' newcomers, Christopher Samba, to fire the ball home.
It was a sweet moment for Stead, who was discarded by Hughes 18 months ago after enduring so many scoreless afternoons and evenings at Ewood Park and not finding goal-scoring much easier elsewhere since leaving.
Blackburn lost their most prolific recent scorer, Matt Derbyshire, with a thigh strain that will keep him out of the England Under-21 side this week, but would have been ahead by half-time if Pedersen had not missed when clean though on the goalkeeper.
Despite the introduction of Dunn, to a welcome fit for a returning hero, Rovers lost their way in the second half. They also lost their other new defender, Stephen Warnock, who saw a second yellow card two minutes from time for a mistimed tackle on Derek Geary.
Hughes thought it was harsh, but thanks to Pedersen's educated left foot two minutes later, he was philosophical about it afterwards. "It's not often you can win Premier League games by not playing to your maximum," he said. "Courtesy of Pedersen, this was one such occasion."Reuse content