An own goal from Angus McDonald and a Sam Hutchinson strike separated the Owls and ten-man Barnsley at Hillsborough.
The conversions came either side of the interval and to cap a miserable evening for the visitors, substitute Adam Hammill saw red for a late challenge on Hutchinson.
Overall, the Owls deserved their return to winning ways and although the Reds looked threatening in part, the result was a fair reflection overall.
The play was end to end through the early exchanges, with neither side stamping any real authority on the derby clash.
Most of the possession was shared in the engine room and it wasn’t until midway through the first half that chances unfolded.
The best opportunity fell to the Tykes when Tom Bradshaw darted in on goal but Keiren Westwood was off his line swiftly to deal with the danger.
Then almost immediately at the other end, an in-swinging Adam Reach corner was met by Steven Fletcher, whose header fell inches the wrong side of the post.
But eight minutes before the break, Wednesday hit the front. Liam Palmer found Lucas Joao in the box and the striker’s effort was inadvertently helped into his own net by McDonald.
Barnsley flew out of the traps for the second half and the Owls were handed a scare when the lively Ryan Kent aimed a delicious free kick into the mix that Bradshaw headed just over.
The hosts introduced Ross Wallace from the bench and the Scot saw plenty of the ball down the right as Wednesday sought a second goal.
Barry Bannan went close with a curling effort that Adam Davies smothered before the Reds countered with Bradshaw forcing Westwood into a diving save.
The Owls were on top in the main and Tom Lees struck agonisingly over the bar from a Wallace corner but Barnsley remained a threat with the score at 1-0.
Substitute Stefan Payne tried an audacious flick to which Westwood was equal, before the game exploded into life as the points were decided.
Hutchinson stabbed home from a Wallace corner on 80 minutes, then Hammill was shown a straight red card to all but end any hopes of a comeback.
Wednesday: Westwood, Palmer, Loovens, Lees, Pudil, Reach, Bannan (Jones 67), Lee, Hutchinson, Fletcher (Nuhiu 78), Joao (Wallace 54)