United's under 18s came from behind to beat Nottingham Forest and make it two wins from two thanks to a stoppage time winner from Kamarl Grant.
Forest took the lead soon after half-time but were reduced to ten men shortly after Hassan Ayari levelled the scores with a free-kick.
The first half saw few chances for either, but Josh Smith went close in the first minute when his shot from the edge of the box was deflected wide.
The Blades struggled to create chances after that but didn't give much up at the other end, Josh Chapman though was called into action to make a good save just before half-time when Forest got in on the United goal.
But soon after half-time the game sparked into life. The hosts took the lead three minutes into the second half when Chapman brought down Korpal inside the box and it was left to Jackson-Davis to slot home from the spot.
It took just five minutes for the Blades to respond though, Ayari curling a superb free-kick into the top corner to get United back in it.
The game further turned on its head when Forest were reduced to ten men, Solomon sent off for a second bookable offence after a rash challenge.
But it was the hosts who looked likeliest to steal the win against a below-par Blades side, that was until Grant calmly slotted home from Ollie Arblaster's free-kick in stoppage time to ensure it was United who went home with the points.
Del Geary: "That was probably as poor as we can play. We dug in and won the game, but we were lucky. I can lose games and accept if we've played well but I didn't see that attitude and mentality today.
"But we're in a development environment and this will be good for me to help them with that. They're young kids, they're learning all the time and today was always going to happen. It's important for them to build on it and learn both on the ball and off the ball."
Blades: Chapman, Ayari, Angell, L. Williams, Grant, Anderson, Smith (Marsh 70), Arblaster, Osula (Bailey-Green 61), Jebbison (Hackford 46), Brooks.
Unused subs: Hampshaw, Cullinan.