United's Under 18s failed to capitalise on a strong first showing against Crystal Palace, a Jake Kelly own goal in the second half ensuring the points were shared on Saturday morning.
Sammy Ompreon's header after 15 minutes had put United in front but several chances came and went before Palace punished the young Blades.
Looking to build on Tuesday's impressive win against Cardiff, United were quick out of the blocks, knocking the ball around well and getting some good crosses into the Palace box.
Crosses were United's main outlet afternoon and the opener came from a corner after Josh Scott saw his header brilliantly saved, Ompreon was on hand to head home the rebound.
Sam Ackroyd went closest to doubling the lead, his header from another United corner was cleared off the line.
Tom Wilson, who scored the winning goal on Tuesday, also went close from a corner as he looked to replicate his goal from the win against Cardiff.
But the missed chances came back to haunt United when Jake Kelly tried to intercept a loose ball and sent it into the back of the net to level the scores.
Leo Gaxha and Antoine Hackford were introduced as the Blades looked to go all out attack, but it was another Wilson header which went closest as the game entered stoppage time.
Ackroyd's deflected free-kick was the last chance of the match, the referee blowing the whistle before the subsequent corner could be taken.
Blades: S. Kelly, Williams, Foulstone, Antwi (Hackford 79), Wilson, Gomis, J. Kelly, Broadbent (Skerritt 46), Ackroyd, Ompreon (Gaxha 64), Scott.