Two goals in 13 second-half minutes from Ryan Lowe and Gary Madine set Wednesday on their way and although sixth-placed County pulled a goal back late on through Lloyd Sam it was not enough to deny the Owls.
The victory lifts Wednesday level with local rivals
Charlton took a sixth-minute lead at Scunthorpe through Bradley Wright-Phillips but were pegged back by Jon Parkin's 21st-minute penalty, while Sheffield United also surrendered a lead at home to Tranmere.
Ched Evans' 31st-minute effort put the Blades in front but a Lucas Akins equaliser just after the break earned
Two of the other sides in the play-off spots were also held to 1-1 away draws, although both
Huddersfield then escaped with a point when Colchester defender Magnus Okuonghae headed into his own net deep into injury time.
Fifth-placed MK Dons also had work to do against rock-bottom Chesterfield after falling behind to a fourth-minute Drew Talbot goal, but the visitors equalised 11 minutes into the second half through James O'Shea.
Carlisle drew 1-1 at
At the foot of the table,
Stuart Beavon netted in the fourth, 61st and 70th minutes to help Wycombe claim a 4-1 win at
Bury had the chance to level the scores up for a second time in the 52nd minute but Giles Coke missed from the penalty spot and Beavon ensured Wycombe would be going away with the points by netting twice more.
Oldham replied through Shefki Kuqi and Reuben Reid but they could not get back on terms and finished the match with 10 men following James Tarkowski's late sending-off.
In Saturday's other matches,