Grant Hanley's fifth-minute strike proved enough for Blackburn to edge past Sheffield Wednesday and claim a first npower Championship win in six matches.
Hanley replaced Morten Gamst Pedersen in Rovers' only change from Saturday's 1-1 draw at Derby and he immediately repaid the faith of caretaker boss Eric Black by opening the scoring from close range.
A solo effort from Lewis Buxton was the closest the Owls came to an equaliser merited on pressure and intent if not clear-cut chances, but Blackburn held on to give Black his first taste of victory at the fifth attempt since Steve Kean's resignation last month.
Rovers vault into the play-off places on goal difference, while Wednesday - winless in the league since August - slip to second bottom by the same means.
Dave Jones' men were soon behind as David Dunn shrugged off the attentions of Wednesday's Everton loanee Ross Barkley, bustled to the byline inside the area and his cutback left Hanley - still up field from an earlier set piece - with a simple finish.
Wednesday came close to levelling either side of the half hour as Miguel Llera struck a 25-yard free-kick narrowly past the post with Paul Robinson beaten, before Michail Antonio got goal side of Bradley Orr and wastefully shot wide.
Dunn limped out of the action after 34 minutes and replacement Ruben Rochina almost had an instant impact, forcing Chris Kirkland into a sharp save from his rasping 30 yarder.
The visitors were on the front foot this time but Rochina almost punished them on the break in the 57th minute, Kirkland saving superbly with his feet after the shot deflected off Daniel Jones.
Fellow full-back Buxton nearly brought Wednesday level in fine style after the hour, cutting into the box inside Dickson Etuhu and thumping past the far post at the end of a surging run.
Wednesday continued to press but Blackburn substitute Pedersen almost gave his side further cheer when Llera hacked the Norwegian's free-kick off the goalline.