The Wednesday Development Squad served up an impressive performance against Birmingham to record their second win in three games, with Claude Dielna and Warren Clarke scoring either side of half time.
To compound the Blues' woes, they were reduced to ten men at Hillsborough as Daniel Clearly was given his marching orders moments before the final whistle.
For Wednesday, club captain Glenn Loovens enjoyed some valuable game time with the Under-21s as he marked his first appearance of the season with a reassuring display following his injury absence.
The Owls asked most of the questions early in the first half, looking sharp and confident in possession.
Sergiu Bus fed Reise Allansani with an incisive pass on ten minutes, only to see the latter's close range shot superbly saved by Connal Trueman.
Moments later, Clarke found his powerful goalbound effort headed off the line by Josh Cogley.
But Wednesday took the lead on 15 minutes through a sublime Dielna free kick from 25 yards.
Birmingham were more purposeful after the break, looking confident in possession and Charlie Cooper flashed a venomous set piece across the face of goal.
George O'Neill came closest to scoring in the space of two minutes, as he firstly forced a fine save from Cameron Dawson, followed by a stinging free kick that rattled the upright.
But Clarke closed the game out for the Owls with an opportunist finish on 57 minutes to seal the points.
Wednesday face a local derby next against Sheffield United on 6 September across the city at Bramall Lane.