It was a tough day at the office for a very young United side that came up against a strong Bolton team that were in fine form.
Braces from Luca Navarro and Mason Birch saw the Trotters to all three points on Saturday.
Inside the opening 10 minutes Bolton found themselves ahead as NAVARRO was played in behind and his low shot found the bottom corner from just inside the area.
United would remain competitive throughout the first-half but were dealt a double blow shortly before the break as BIRCH scored twice in as many minutes with a pair of close range finishes putting the hosts in control.
The second-half saw the Blades push forward to try and get themselves back in the game but were reduced to long range efforts by a compact Bolton side.
Wanderers would finish the scoring with 20 minutes to go as NAVARRO picked up the ball and curled into the top corner from the edge of the area.
Blades: Dewhurst, Portman, Foulstone, Williams, Gordon (Belehouan 80), Neal, Broadbent, Ackroyd (J. Kelly 80), Potts, Oure, Joash (Capello 45).
Unused: S. Kelly.