The hosts had shown plenty of intent in the opening stages, but the Black Cats were unfortunate to put their visitors ahead after seeing a number of their own crosses impressively repelled.
Tyler Morton’s free-kick delivery caused havoc in the Sunderland box, with Ross Stewart’s header rebounding off Dennis Cirkin’s face, back onto the Scotsman and past Anthony Patterson.
It only took Stewart three minutes to make amends for his role in the opener, luring John Buckley into conceding a penalty that he clinically converted to score in back-to-back games after returning from injury.
Rovers' frustrations were encapsulated when Morton unnecessarily got himself booked for swiping Jack Clarke’s legs, and neither side was able to produce much quality as the rest of the half was played out.
A positive run from Clarke shortly before HT opened up an opportunity for Patrick Roberts, who tamely dragged his shot wide.
There was early promise from both sides in the second period, although that was joined by concern as Cirkin went off injured and Ben Brereton Díaz had problems with his ankle.
The Black Cats are yet to score from a corner this season, and Stewart looked like changing that at the 102nd attempt until his shot was blocked by Harry Pickering.
Getting their fans in full voice, Sunderland were beginning to build up momentum but Stewart couldn’t quite apply the finish again after Clarke had driven forward well.
At the other end, Bradley Dack’s inventive pass found Morton in a dangerous position, before Patterson produced a strong save to deny the loanee.
Sunderland looked more likely to secure victory in the latter stages as Blackburn tried to hang on.
However, some cynical fouls came back to haunt them as after having won a free-kick, Daniel Ballard fought to keep the ball alive and Ellis Simms calmly poked the ball into the bottom corner in the 91st minute.
A dramatic Boxing day saw Tony Mowbray’s side record their first win in three games, while Blackburn were outpunched again, having now lost four of their last five in all competitions.
