Karlan Grant’s precise penalty in the 13th minute set Huddersfield on their way but Tommy Elphick’s poor pass led to an equaliser for Lewis Holtby eight minutes later – his first on his full debut for the club.
The German then set up Bradley Dack, whose super strike completed the comeback in the 33rd minute, but Bacuna changed the game within six minutes of his introduction, netting with a left-foot strike in the 63rd minute for his third goal of the season.
Curacao international Bacuna has scored in three successive games and after the draw, Cowley praised his game-changing ability, whilst praising the whole team’s effort.
He said: “Juninho Bacuna gives us a real impact off the bench. He’s got so much to give as a player.
“He came on again and changed the game. He adds that bit of a difference. You want a sexy bench and great options and he fits the bill.
“He obviously wants a start and we’re working on that. He has all the tools but sometimes we want him to use the hammer and screwdriver and he uses something else. But it will come good.
“We had 13 attempts, they had 12 so it was quite even, but we know we were coming away to play a good team, so this is a positive result for us.
“Four unbeaten (in the league) is really pleasing, this game was a big challenge for our team against an experienced Blackburn side. It was a real tactical battle but we showed fortitude, determination and application and got a result.”
Rovers remain in mid-table after stretching their winless run to four. It is now five games without a clean sheet and Tony Mowbray called for greater consistency of performance. He said: “Ultimately we’re disappointed. After going down so early to a penalty, we perform at a high level in the first half, but we have to strive for consistency over 90 minutes.
“It’s difficult to maintain the levels and yet, we should be able to win lots of football matches playing at the level we did in the first half.
“Second half, you have to give them credit. They swung the momentum their way. I’m disappointed to lose the second half 1-0 because we could have been out of sight by then really.
“Credit to Huddersfield, they’re on a decent run. If we’d have played them seven games ago, we wouldn’t have had to play as well and still won. But Dan and his coaching team have given them belief.”
Blackburn Rovers: Walton, Nyambe, Adarabioyo, Williams, Bennett, Travis (Rothwell 71), Johnson, Downing (Evans 80), Holtby (Gallagher 71), Armstrong, Dack. Unused substitutes: Graham, Leutwiler, Rankin-Costello, Buckley.
Huddersfield Town: Grabara, Simpson, Elphick, Schindler, Jaden Brown, Chalobah (Bacuna 57), Hogg, Diakhaby (Hadergjonaj 86), O’Brien, Kachunga, Ahearne-Grant (Campbell 83). Unused substitutes: Pritchard, Mounie, Stankovic, Schofield.
Referee: D Bond (Lancashire).