The Italian proved Wednesday's match-winner at the John Smith's Stadium, but only after a tactical tweak from head coach Carlos Carvalhal.
Wednesday were without key middle men Barry Bannan and Sam Hutchinson for Saturday's trip to West Yorkshire, in which they recorded a 1-0 win courtesy of Forestieri's 83rd-minute winner.
The pair's absence saw Alex Lopez and Aiden McGeady fill in, and chances were few and far between for Carlos Carvalhal's team.
Second-top scorer Gary Hooper found himself isolated up front, prompting his withdrawal in the 68th minute.
But the Owls finally made their breakthrough seven minutes from time, after substitute strikers Atdhe Nuhiu and Lucas Joao combined to allow Forestieri to slide home at the far post.
And Forestieri conceded to the Sheffield Star: “Huddersfield was a very hard game because they defended very well. Our strikers and midfield did not play so good. They are a very similar team to us.
“We were lucky enough to get the win but we need to improve. Every game you learn something. We need to correct some mistakes we did.
“But we need to enjoy this moment and then think about Tuesday as we have seven games this month.”
Bannan sits out the final game of his suspension against Blackburn Rovers on Tuesday, where fifth-placed Wednesday will be looking to take advantage of tough fixtures for their closest rivals.
Fourth meets sixth at the KC Stadium as Hull City host Derby County, while seventh-placed Cardiff City travel to league leaders Burnley.
The Owls are currently three points clear of Cardiff, who visit Hillsborough later this month.