Wednesday suffered their maiden defeat of the season and paid the price for failing to turn dominance into goals at Morecambe.
Substitute Ryan Delaney settled what for large parts was a one-way contest as the Owls controlled the game after a promising start from the Shrimps.
But for all their purpose and guile, Wednesday fell short in the final third and Delaney’s second half goal proved the difference.
The Owls went into the contest protecting the best defensive record in the country and lived up that billing as Morecambe applied the first bouts of pressure.
Dangerman Cole Stockton, with six goals already this season, tested Bailey Peacock-Farrell from a set piece and twice the hosts threatened from quickfire corners.
But Wednesday grew into the game and Shrimps skipper Sam Levelle had to be alert to thwart Lee Gregory from the Owls’ first attack as the striker pulled the trigger eight yards out.
Jaden Brown went close with a cross cum shot moments later and Jack Hunt hit the top of the bar with a floated effort towards the back post.
Wednesday’s neat passing game was causing concerns in the Morecambe rearguard and the breakthrough almost came right on the half time whistle as Gregory glanced a header inches wide from a whipped Marvin Johnson cross.
The Owls went closer still just three minutes into the second half through George Byers. The midfielder chanced his arm 25 yards out and beat Jokull Andresson all ends up but the ball cannoned to safety off the upright.
Still the visitors pressed forward and Gregory hit narrowly over after swivelling to shoot in the box before Brown was halted in his tracks by the outrushing Andresson.
The Morecambe shot-stopper dived to his right to prevent the ever-busy Gregory breaking the deadlock on the hour as Wednesday stayed in the driving seat.
The only thing missing was the goal but alas for the Owls it came at the other end. Adam Phillips swung a corner into the heart of the danger zone and Delaney bundled home almost on the goal line.
It was the Wednesday’s first concession of the campaign, the first time they have been behind, and the first question of its kind.
Darren Moore made an immediate double change, with Florian Kamberi and Theo Corbeanu introduced from the bench. Lewis Wing also came on as the Owls looked to fashion an equaliser.
But try as they might, with Gregory remaining the main threat, Wednesday were out of luck and the final action of note saw Stockton then Arthur Gnahoua squander chances but it mattered not as the hosts triumphed in front of their highest attendance in history.
Wednesday: Peacock-Farrell, Hunt, Iorfa, Palmer, Brown (Kamberi 65), Bannan, Byers, Adeniran (Wing 74), Johnson, Paterson (Corbeanu 65) , Gregory