United's U18s picked up all three points in the junior Steel City derby on Tuesday afternoon.
A David Parkhouse strike, a Jordan Doherty spot kick and a Connor Cutts header paved the way for a deserved victory at Middlewood Road.
But it was the hosts who almost had the lead within two minutes as Belehouan's back pass rolled under Warhurst's foot but luckily bounced off the post.
The only other action of note in the ensuing 43 minutes, was Potts half volleying wide from a promising position.
However, in the fourth minute of stoppage time at the end of the first-half Cantrill's ball over the top saw PARKHOUSE in the clear and he out muscled the defender before slotting home to give United the lead.
Parkhouse was at the forefront once again early in the second-half. He beat Weaver to a through ball and got clattered by the Owls keeper for a penalty. DOHERTY kept his cool from the spot sending Weaver the wrong way on 51 minutes.
Wednesday tried to force their way back into the game but couldn't find the net with Reaney firing over following a corner and a Gavrilov effort was cleared off the line by Portman.
With 71 minutes played the Blades added a third as Cantrill's long throw was headed on by an opposing player and found CUTTS at the back post who headed home from close range to seal the victory.
Blades: Warhurst, Portman, Cantrill, Broadbent, Cutts, Belehouan, Hawkes (Kelly 32), Doherty, Parkhouse, Lawrence (Capello 88), Potts (Ompreon 77).
Unused: Dewhurst, Weaver