The Owls slipped to a 1-0 defeat against Chesterfield in the early kick-off at the B2net Stadium.
A late penalty converted by Dean Morgan decided the local derby, as well as condemning the Owls to their third straight league defeat.
Wednesday made two changes as Reda Johnson made his return from suspension, while Ryan Lowe was given the nod to start up front.
It was the Owls who made the brighter start of two sides as Chesterfield struggled to deal with Wednesday's attacking threat.
The early possession was dominated by the visitors and Lowe almost gave the Owls an early goal but his header from Reda Johnson's cross landed just over the crossbar.
A clever throughball from Chris Lines then cut the Spireites' defence open as Reda Johnson found space in the area to shoot but Tommy Lee made a vital stop to keep the scores level.
Wednesday's grip on the game continued to increase and the only thing missing from their performance was the opening goal.
A deep corner from Lines needed a crucial interception at the back stick from Liam Ridehalgh to prevent Lewis Buxton from heading home from close range.
Chesterfield's first sight of goal came just before the half hour mark when Ridehalgh got good connection on his strike from distance but Stephen Bywater produced a stunning diving save to tip the ball over.
But back came Wednesday at the other with Lowe, who was unlucky not to have won a penalty when the striker appeared to have been brought down in the area by Lee.
Lowe had one more chance before the break when the lively striker managed to find room in the area to turn and shoot but fired the wrong side of Lee's near post.
The Owls made their first change of the game ten minutes after the restart with Gary Madine replacing O'Grady.
Bywater was once more called into action saving low from Drew Talbot's driven strike as the SPireites began to edge their way into the game.
Clinton Morrison was then introduced and almost made an immediate impact but saw his strike blocked out by Chesterfield bodies at the back.
Danny Batth then made a brave block to keep out Dean Morgan's strike inside the area before Madine saw his effort from the angle fly over Lee's goal.
But the key moment of the game came 13 minutes from time when John Bostock clashed with Nicky Ajose in the area and the referee pointed to the spot; with Morgan slotting home from 12 yards.
Wednesday almost responded immediately as Rob Jones saw his towering header cleared off the line.
With time against Gary Megson's men, the Spireites defended in numbers and a late scramble in the area would not fall for the visitors as Madine's eventual effort drifted wide of the targets.
Chesterfield: Lee, Ford, Trotman, Thompson (Morgan 45), Robertson, Ridehalgh, Davis, Allott, Talbot, Ajose, Lester (Westcarr 85)
Substitutes: Flemming, Bowery, Whitaker
Owls: Bywater, Buxton, Batth, Jones (C), R Johnson, Prutton, Lines (Morrison 66), Semedo, J Johnson (Bostock 25), Lowe, O'Grady (Madine 54)
Substitutes: Weaver, Llera