United's U21s slipped to a narrow defeat in a five-goal thriller at Hillsborough on Tuesday night.
Gary Madine struck twice in the first-half to put the Owls in control at half-time. Rodri added a third in the second-half either side of a brace from Danny Philliskirk. The Owls also missed a penalty in the latter stages.
The home side took the lead in the ninth minute when Mayor teed up MADINE who slotted the ball past the advancing Willis.
United enjoyed their share of possession as the first-half progressed and were unfortunate to fall two behind in the 38th minute. Lavery broke down the right before cutting the ball back for MADINE and the striker fired the ball into the roof of the net from close-range.
The Blades were positive from the off after the break and after Miller had forced Wednesday stopper Jameson into action, PHILLISKIRK reduced the deficit, sweeping the ball home after some good footwork from the former Crewe man.
The visitors were now definitely on the front foot and had a few half chances to draw level, but Chris Morgan would have been disappointed to see RODRI restore Wednesday's two goal advantage in 74th minute after Mayor had advanced beyond the Blades defence.
There was still time for two more notable pieces of action; firstly the Owls spurned the chance to add to their tally when Lavery launched a penalty handsomely over the bar after Willis had upended Grant in the box.
In injury-time PHILLISKIRK got a deserved second for the Blades, the least their efforts warranted.
Blades: Willis, Westlake, McFadzean, Harriott, Salt, Kennedy, Chapell (De Girolamo 76), McAllister, Porter (Ironside 59), Miller (Tonne 76), Philliskirk.
Unused: Lynch, Pemberton.