Wednesday's Development Squad slipped to a first defeat in six games, going down 2-1 against Crewe.
Crewe's Billy Bingham negated Gary Hooper's opener for the Owls and wideman Charlie Kirk completed the turnaround for the visitors soon after.
An uneventful and scrappy affair unfolded at Middlewood Road on a damp and windy Monday afternoon until Wednesday's first shot was dragged wide by James Murphy on 15 minutes.
Three minutes later, Crewe looked for an early lead but Dan Wallis' superb stop from a corner kept the game scoreless.
But the hosts went ahead on 39 minutes after Connor Kirby stole possession 35 yards out and freed Hooper, who tucked home with style.
The Owls began the second period 1-0 ahead but the game swung in Alex's favour via two goals in the next eight minutes.
First, on 47 minutes, Bingham glanced home from a looping 30-yard free-kick, before Kirk then found space to curl in from distance eight minutes later.
Wednesday almost got back on terms on 69 minutes when Jack Stobbs sprinted purposefully down the left to float a cross into the danger zone, but an onrushing Ashley Baker saw his well-taken attempt blocked.
Neil Thompson's men next travel to Hull on 6 March as they bid to return to winning ways and cement their place at the top of the table.
Wednesday: Wallis, Baker, Emanuelson, Murphy (Clarke 76), O'Grady, Thorniley, Stobbs, Kirby, Hooper (Preston 65), Willard (Hirst 55), Buckley