Despite taking the lead in each half, United's U18s had to settle for a point at Middlesbrough on Saturday.
Substitute Liam Wilkinson finished off a good move to put the Blades in front late in the first-half, only for them to concede direct from the restart, this was replicated in the second period after Matty Darlow had volleyed home.
It was an open game from the off, in perfect conditions between two coveted Academies, with both teams playing some excellent passing football.
After having to replace the ill Murray in the 22nd minute, the visitors had five attempts on goal in quick succession, with Foster, Slew and Gregory all coming close.
Chappell was causing the Boro defence problems and he, in 40th minute, linked up with WILKINSON, who finished well after some neat build-up play. Within a minute Boro were level when poor defending allowed BROBBEL to beat Billard from close-range.
United took the game to the home side after the break and Maguire came close from a Chappell corner.
In the 74th minute United regained the lead. A Chappell corner found Maguire and his header was skilfully volleyed home from inside the box by DARLOW.
It was then a case of déjà vu, when MURPHY took advantage of some poor defending to draw Boro level for a second time within a minute of conceding.
With virtually the last kick of the game Slew almost got the goal his performance deserved, but his shot was agonisingly wide after he had danced past two defenders.
Coach Kevin Fogg says his youngsters must learn how to defend once in front after seeing his side twice throw away the advantage: "We must learn how to win games, especially after working so hard to get in front. The lads know that we will be working on that in training and it is all part of their development."
Blades: Billard, Brown, Roe, James, Darlow, Maguire, Chappell (O'Kane 80), Murray (Wilkinson 22), Foster (Lammy 70), Gregory, Slew. Unused: Andrew, Kennedy.