United's U23s saw their 100% record in the Central League Cup ended by Bradford City on Wednesday afternoon.
But the narrow loss at the Look Local Stadium, courtesy of Reece Webb-Foster's first-half strike didn't affect the Blades final position in their group.
United progress to the semi-finals as group winners with nine points from four matches. They are joined in the last four by Chesterfield, Fleetwood Town and Wigan Athletic.
The Blades had the game's first chance in the 14th minute. After good work down the right from Crofts, Hallam was denied by a good save from Cracknell.
In the 26th minute, it was City who opened the scoring though, as WEBB-FOSTER produced a composed finish past Eastwood from inside the penalty area after Gilliead had recycled the ball from Hudson's free-kick.
Before the break, Crofts and Reed had sights of goals for the hosts and Graham should have done from a set-piece, heading straight at Cracknell from a promising position. At the other end, Eastwood was alert to deny goalscorer Webb-Foster.
On the hour, Gilliead whipped a cross into the box that deflected off Kelly's head and onto the crossbar. In response, from Hallam's inviting delivery Graham headed narrowly wide under pressure.
The game was delayed for six minutes following an accidental clash between Webb-Foster and Eastwood, which saw the United stopper forced off the field and having used all five substitutions, as is permitted in this competition, Graham ended the game in goal and the Blades finished with ten-men.
Blades: Eastwood, Bennett (Charlesworth 45), Kelly, Graham, Cummings (Doherty 60), Semple, Crofts (Mallon 60), Reed, Hirst (T Smith 45), Hallam, Ford (Slater 45).