Goals from Junior Hoilett and Ayegbeni Yakubu gave Rovers a crucial win at Ewood Park.
The hosts' perilous position meant they needed the points more than their opponents and they certainly showed more ambition to win the game.
Hoilett's volley broke the deadlock just before the hour and after Black Cats substitute Ji Dong-won missed from four yards, Yakubu headed his 14th Premier League goal late on.
Hoilett's time at Ewood could well be coming to an end shortly but his parting gift could yet be to keep the club in the top-flight.
The 21-year-old seems increasingly unlikely to renew a contract which expires on the summer.
Hoilett's contribution in recent weeks, however, has been invaluable. He struck twice against Wolves in their previous outing and his well-taken goal on Tuesday was followed by a late Yakubu header to give Rovers an important victory with nine games remaining.
Hoilett looked the most inventive of Blackburn's players on the night and although manager Steve Kean still speaks optimistically about keeping him beyond the end of the season, there are bigger clubs waiting in the wings to snap up his prize asset.
The man-of-the-match aside, Rovers laboured in the first half as Sunderland - with only two changes from the side which drew at Everton on Saturday - looked like they were feeling the after-effects of their FA Cup quarter-final exertions.
The home side had spent some of the 10 days since the 2-0 win at Wolves on a team-building break in Yorkshire and they certainly looked fresher.
But they failed to capitalise on that and some sluggish play let the Black Cats off the hook as the visitors finished the first half much more composed than they started it.
It was a similar tale after the break until Hoilett's quality broke the deadlock, although Sunderland substitute Ji will be wondering just how he missed an open goal late on just before Yakubu added the decisive second.
Players from both sides showed Fabrice Muamba was on their minds as they wore 'Pray for Muamba' T-shirts in the warm up
When the action started, Blackburn threatened after only three minutes when Hoilett slipped a pass through to Yakubu - whose shot was only half-saved by goalkeeper Simon Mignolet and had it not been for Phil Bardsley getting back to hook clear the ball would have crept inside the near post.
The Olsson brothers, Martin and Marcus, initially looked like posing a threat down the left with the former exchanging passes with his elder brother before racing into the penalty area to shoot from the narrowest of angles and then firing over the rebound.
Grant Hanley flashed a near-post header over from Morten Gamst Pedersen's set-piece, Hoilett drilled two attempts from a free-kick into the defensive wall and Mauro Formica volleyed wide.
Sunderland's one half-chance came in the 35th minute when James McClean swung in a pinpoint first-time cross from the left to Fraizer Campbell and only a perfectly-timed tackle from Hanley prevented the striker unleashing a shot from 10 yards.
Blackburn were the first to show in the second half, with Formica meeting Pedersen's cross after the first bounce to fire in a shot which Mignolet turned behind.
But the Sunderland goalkeeper was partly at fault for Rovers' opener in the 58th minute, although credit must go to Hoilett for his instinctive finish.
Pedersen directed his long throw at the six-yard box but Mignolet's punch went straight to Hoilett, who volleyed the ball straight back into the net.
Another Pedersen long throw three minutes later saw Scott Dann head just wide of the far post as Rovers tried to press home their advantage.
Martin Olsson produced a crucial tackle to beat Nicklas Bendtner to the ball just three yards out and prevent a certain equaliser, but substitute Ji should have levelled things up from close range in the 77th minute from McClean's centre.
Four minutes from time, the result was assured when Rovers substitute Bradley Orr crossed from the right for Yakubu to head home his 14th league goal.
It clinched back-to-back victories for the first time since November 2010 and Rovers' first successive clean sheets since August that year, further raising hopes of escaping relegation.