Stephen Caldwell's first goal for Leeds set them on their way to a key win.
Caldwell headed home Gary Kelly's cross as Leeds started strongly - Alan Smith also forcing a great save from Brad Friedel with a 25-yard drive.
James Milner hit the crossbar for the in-form Yorkshiremen, before two late goals, one at each end.
Mark Viduka made it 2-0, converting Jermaine Pennant's cross, before Craig Short headed a consolation from Paul Gallagher's free-kick.
Blackburn have not won at home since 29 November and now find themselves fighting for their Premiership survival.
Only goal difference separates Blackburn, Portsmouth and Leeds, who are all three points ahead of second-bottom Leicester.
Leeds remain in the relegation zone but are now in with a real chance of avoiding the drop that seemed inevitable only a short while ago.
Graeme Souness made four changes to his line-up, recalling Lorenzo Amoruso and Lucas Neill in defence as he looked to shore up his team's porous backline.
But it took Leeds just two minutes to open the scoring against a team who have only kept four clean sheets in the Premiership this season.
Pennant's determined run won his team a corner, which was played short to the recalled Kelly.
The Irish defender delivered a deep cross to the far post for a completely unmarked Caldwell to head past Friedel.
Smith almost doubled the visitor's lead after nine minutes following a poor defensive clearance.
The Leeds forward struck the ball on the half volley from 25 yards, forcing Friedel into an acrobatic save.
While Leeds started with confidence, Blackburn mustered virtually nothing in the opening phase save a long-range shot from Neill that drifted wide of Paul Robinson's goal.
Rovers midfield struggled to assert itself on the contest, depriving Andy Cole and Jon Stead of quality service.
In a rare moment of attacking intent Cole's intelligent header across goal was volleyed straight at Robinson by Stead.
But Johnson came close to doubling Leeds' advantage with a snap-shot that flew narrowly wide of Friedel's goal, while Kelly drove just over the crossbar.
Johnson limped off injured shortly after half-time to be replaced by Eirik Bakke, who has just recovered from a thigh muscle problem.
But the substitution did not diminish Leeds' attacking relish, with Smith's mazy run taking him into the Rovers' penalty area.
Smith laid the ball off to Milner, whose shot crashed off the underside of the crossbar and bounced off the goal-line with Pennant unable to convert the rebound.
2 mins: Caldwell opens the scoring
9 mins: Friedel brilliantly denies Smith
58 mins: Milner hits the crossbar
89 mins: Viduka doubles Leeds' lead
90 mins: Short pulls one back
Brett Emerton's first decent cross picked out Cole, whose delicate touch was smothered by Robinson as Blackburn started to find some form.
But Leeds continued to press and after Mark Viduka got the better of Amoruso, the Australian striker pushed his shot frustratingly wide of Friedel's goal.
Blackburn almost levelled close to full-time, Cole's overhead kick brilliantly saved by Robinson.
But with the final whistle looming Leeds sealed the points.
Pennant crossed from the byeline, Smith cleverly let the ball run and Viduka slotted home.
There was still time for Short to head substitute Gallagher's free-kick past Robinson but it was no more than a consolation.
Blackburn: Friedel, Neill, Amoruso, Short, Gray, Emerton, Tugay, Flitcroft, Reid (Gallagher 45), Cole, Stead (Jansen 68).
Subs Not Used: Todd, Andresen, Enckelman.
Booked: Gray, Flitcroft.
Leeds: Robinson, Kelly, Caldwell, Duberry, Harte, Pennant, Seth Johnson (Bakke 56), Matteo, Milner, Smith (McPhail 90), Viduka.
Subs Not Used: Radebe, Simon Johnson, Carson.
Booked: Matteo, Milner.
Referee: S Dunn (Gloucestershire).