Steve Kean's side were widely written off as relegation certainties after a miserable first half of the season, but Rovers have found some momentum at just the right time and they are now six points clear of the bottom three.
David Hoilett opened the scoring early in the first half and Nigerian striker Ayegbeni Yakubu sealed the points in the closing minutes to pile the pressure on Blackburn's relegation rivals.
Sunderland boss Martin O'Neill handed Greek defender Sotirios Kyrgiakos his debut almost two months after the former Liverpool star joined the Black Cats on loan from Wolfsburg.
Kyrgiakos replaced the injured John O'Shea and was in the thick of the action early on as Rovers took the game to the visitors.
Kean's side, who have now taken seven points from their last three matches, started with an incisive move as Hoilett slipped a pass through to Yakubu.
Yakubu lashed in a powerful strike and, although Simon Mignolet got a touch to the shot, the Sunderland goalkeeper could not prevent it going past him.
However, Yakubu watched in frustration as Sunderland defender Phil Bardsley got back to hook clear.
Martin Olsson then exchanged passes with older brother Marcus down the left to race into the penalty area and force another save from Mignolet.
Rovers threatened again when Grant Hanley flashed a header over from Morten Gamst Pedersen's free-kick, while Mauro Formica volleyed wide after the Black Cats failed to clear Pedersen's long-throw.
There was no let-up from Rovers in the second half and Formica drove in a shot which Mignolet turned behind.
Blackburn's pressure was finally rewarded in the 58th minute.
When Pedersen launched a long throw into the penalty area, Mignolet's attempted punch clear fell to Hoilett and he volleyed home from 12 yards.
South Korea's Ji Dong-Won had Sunderland's best chance in the 77th minute but blazed over from just four yards with the goal at his mercy.
And Yakubu sealed the points in the 86th minute when he headed home his 14th league goal of the season from Bradley Orr's cross.