United's U21s slipped to defeat against leaders Nottingham Forest, despite a gutsy performance at Shirecliffe on Monday.
In a game where there was very little between the two sides, a couple of second-half set-pieces settled the game in the visitors favour.
On a wet and windy day at Shirecliffe, both teams battled to get a grip of the game in the opening exchanges, although goalscoring opportunities were at a premium.
As the opening 45 minutes ticked by, both sides got into some promising situations, but United's defence, marshalled excellently by Shaun Barker rarely looked like being breached.
At the other end, Coustrain and Adams combined to create an opportunity from the right, whilst the Blades failed to capitalise on a couple of excellent dead ball deliveries from Ben Davies.
The second-half, saw Forest immediately on the front foot and they took the lead in their first attack from the restart. From a right-wing corner, the visiting attacker got across his marker and beat Willis to an attempted with a header at the near post.
The visitors extended their lead five minutes later from another set-piece. A free-kick from the right-wing was whipped in with pace and it was unclear whether or not it was headed in on route to the back of the net.
United had chances to bring themselves back into the game, Dimaio shot wide when well placed, whilst substitutes Cockerline and Hamilton tried in vain to give the home side a lifeline.
The final meaningful action, saw Ben Davies come close with a long range free-kick, but the Forest goalkeeper produced a save for the cameras as his side left with the points.
Blades: Willis, Davies, McFadzean, Dimaio, Barker (Evans 61), Whiteman, Adams, Reed, Shirdel (Hamilton 61), K. Wallace, Coustrain (Cockerline 72).
Unused: Eastwood, Scarisbrick.