Makhtar Gueye's only goals for Blackburn had come in the Carabao Cup
Makhtar Gueye's first Championship goal gave Blackburn Rovers victory at Sheffield Wednesday - their fifth consecutive win.
The Senegalese striker, signed from Belgian club Molenbeek in July, scored midway through the second half.
Wednesday failed to properly clear Ryan Hedges' cross from the left and, after retrieving the ball on the opposite flank, Joe Rankin-Costello crossed for Gueye to head home from close range.
The result strengthened Rovers' position in the top six and continued the Owls' poor home form.
Danny Rohl's side have now won just two of their past 10 league matches at Hillsborough.
In the build-up to the game, Rohl declared "our mindset is not right at home" and suggested his team needed to be more direct, but he did not get the response he wanted.
There were few openings before both teams hit the bar in quick succession late in the first half.
After Owls goalkeeper James Beadle punched Todd Cantwell's corner straight to Lewis Travis, the Rovers midfielder's strike from near the edge of the penalty area crashed against the woodwork.
Three minutes later, Yan Valery almost put the hosts ahead when his header from Shea Charles' corner also struck the bar.
And before the interval Wednesday went close from another corner, this time when Barry Bannan's delivery was headed just off-target by Di'Shon Bernard.
Wednesday pushed hard for an equaliser after going behind but Blackburn have been resolute at the back amid their fine form.
This was their fourth successive 1-0 win - and they again defended superbly to keep a clean sheet.
Rovers keeper Aynsley Pears kept out a header from Michael Smith and Bannan curled a late free-kick wide of the near post.
In contrast to their problems at home, Wednesday have won four of their past five away matches. They are back on the road this weekend, when they visit Oxford United.
Blackburn are at home to Luton Town.
Sheffield Wednesday boss Danny Rohl told BBC Radio Sheffield:
"It's again the same story. We are feeling so close and then there's that last punch, at the last moment. In these games, we are unable to do this.
"It's sometimes hard to take when you see what we invest into the game again and again, then I feel for my team. They do everything what I demand from them, they fight for every inch again and again until the end.
"But this last step, it's a big last step - I think that should be clear for us. This is not a small step, it's a huge step and it's the reason some teams have a flow to take wins and some teams are in the middle of the table.
"If we can improve this, then we can go high up."
Blackburn boss John Eustace told BBC Radio Lancashire:
"I'm really delighted for Makhtar to get the winning goal.
"He's been working his socks off in training and in the games when he's come on. It's a fantastic ball from Joe Costello and what a great finish.
"Any striker wants to score goals but I think you could see by his work-ethic and the way that he keeps going that what he does for the team is excellent.
"It was a really scrappy Championship game where there wasn't a lot of chances. We had to defend a lot of balls into the box.
"The way we defended was really pleasing and the bit of quality was with us, with the cross from Joe and the build-up."
