Wednesday's development squad surrendered a one-goal lead to lose 2-1 to Bolton Wanderers in their top of the table clash at Middlewood Road.
On a cold and blustery day, Neil Thompson's men went ahead in the second minute when Freddie Neilsen stabbed home from close range after the visitors failed to deal with a corner. The Danish defender's goal comes just a week after he made his Owls senior debut in the FA Cup against Carlisle United.
But Bolton responded well to going behind and Connor Hall, formerly of Sheffield United, blazed over after a quickly taken free-kick.
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Wednesday then threatened on the counter attack and Warren Clarke slipped in Matt Penney but James Aspinall was equal to his left foot drive.
However, the Trotters handled the windy conditions better and Liam Morris skipped past a couple of challenges before curling a left foot strike from long range narrowly wide.
Moments later, Harry Charsley sent Jeff King scampering away down the left flank and his cross from the byline was expertly cleared away at the back post by Clarke.
Bolton kept piling on the pressure and it was no surprise Hall levelled things up in the 35th minute, rising highest to head in Ryan White's fine centre.
Hall almost grabbed a second, side-footing inches off target after more neat approach play.
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The visitors continued to dominate after the break and King completed the turnaround, lashing home from 10 yards.
Thompson threw on Fraser Preston and Jack Stobbs but the Owls, watched on by assistant manager Remy Reynierse, created little. Sean Clare, the pick of the bunch in midfield, glided forward only to steer a left foot effort over the top.
Wednesday were outplayed and second best for long periods and Bolton held on for a deserved three points. The result means the Trotters leapfrog the Owls into top spot in the Professional Development League Two North table on goal difference.
Owls: Wallis; Baker, Nielsen (Lee 79), O'Grady, Clarke; Waldoch, Murphy (Stobbs 57), Clare, Kirby, Penney; Borukov (Preston 53). Substitutes: Walker, Williams.