New signing Simon Vukcevic scored his first Blackburn goal as they edged past League One side Leyton Orient in the Carling Cup third round at Ewood Park.
Jason Roberts put the hosts ahead with a penalty just before half-time after Martin Olsson had been brought down.
David Mooney equalised after the break but Ruben Rochina made it 2-1 with a simple tap-in and Vukcevic drilled in to extend the lead.
Dean Cox added a late goal but it was too late for Leyton Orient.
Blackburn manager Steve Kean was confident enough to make eight changes to the side that beat Arsenal on Saturday, and it paid off with back-to-back wins for the first time since 8 January. The weekend protests must seem a long time ago.
Rovers were always the better side in the first half and deserved their interval lead through Roberts from the penalty spot.
Orient were made to wait for their hosts to reappear for the second half but whether it was that which spurred them into life or manager Russell Slade's words at the interval, they came out more positively.
And Mooney levelled in the 64th minute with a smart finish from George Porter's cross.
But January signing Rochina and Vukcevic, who joined last month, put the game beyond the visitors' reach.
Roberts' shot was half-saved by keeper Lee Butcher, leaving Rochina to roll the ball into an empty net for his fourth strike in as many matches. Then Vukcevic scored a wonderful goal after Ryan Lowe's cross was only half-cleared.
Cox found the net late on to leave the Blackburn fans sweating, his shot going in off the post with three minutes remaining, although it came too late to force extra time.