United's under 18s fell to their first defeat of the season but fought until the end despite playing over 40 minutes with nine men.
Centre-back duo Kamarl Grant and Luther Williams both received red cards either side of half-time to make it a monstrous task for the young Blades against a Wigan side who won the league last season.
Despite the two-man deficit, Del Geary's side fought right until the end and had enough chances to steal something on a day where it could and should have been so different.
It was far from a perfect start as the Blades fell behind to a simple back post header less than 90 seconds, but United got on top of their opponents soon after and levelled it up after 15 minutes.
Femi Seriki, who was a threat all game down the right, was tripped in the box and Frankie Maguire stepped up to emphatically hammer home from the spot.
But the Blades found themselves trailing once again, another close-range finish after a shot from the edge of the box deflected kindly into the path of a Wigan forward.
The afternoon began to spiral soon after when Grant was shown a straight red for an off the ball incident, before Wigan added a third with a stunning half volley from the edge of the box.
It did look like the Blades had got a goal back before the break when Andre Brooks' corner appeared to creep over the line, the referee though blew for a foul despite no Blades player appearing to be too near to the goalkeeper.
If that task was hard, it became almost impossible after the break when Williams also saw red for bringing down his man as Wigan broke through on the United goal.
Down to nine men, it would have been easy for Wigan to assert their advantage, but the Blades put in a terrific and spirited performance to almost fight back and clinch a point.
Substitute Hassan Ayari was particularly lively, forcing a stunning save out of the goalkeeper before curling an effort from a similar position just over the bar.
Fellow substitute Harvey Cullinan saw a header saved before Maguire drove an effort wide, the Blades looking like the team who had the numerical advantage.
The goal did come when Daniel Jebbison headed home Maguire's cross in the first minute of stoppage time, and despite late pressure and a number of crosses into the box, the Blades weren't able to get the equaliser their efforts deserved.
Blades: Chapman, L. Williams, Angell, Arblaster (Ayari 46), Grant, Anderson, Seriki, Maguire, Jebbison, Osula (Cullinan 49), Brooks (Th. Williams 80).
Unused: Hiddleston, Marsh.