John Pemberton's youngsters, who were leading one nil from the first leg and win the tie 3:0 on aggregate, made history on Wednesday evening by becoming the first ever Blades team to reach the FA Youth Cup Final.
The showdown between United and Villa was at Bramall Lane in front of a healthy crowd (4,000), most of whom were Unitedites.
Two goals from skipper Elliott Whitehouse ensured the Blades would be opponents to either Manchester United or Chelsea in the two-legged final, dates to be confirmed.
Whitehouse's first came on the stroke of half-time after neat play from Maguire at the byline allowed the captain to slot the ball past the stranded Villa keeper after Kennedy's knock-down.
Many familiar faces were in the crowd to see the Blades extend their lead after Villa keeper Barratt was dismissed after bringing down Ironside in the area - Whitehouse converted his penalty to send the Blades into an assailable 3:0 aggregate lead, but his celebrations were dampened when he was yellow carded for taking his shirt off amidst the celebrating.
Blades boss Micky Adams was in attendance alongside assistant Alan Cork. A Villa pairing of Gerard Houllier and Gary McAllister were also keeping a watchful eye, as were Scunthorpe manager Alan Knill and former Charlton manager Phil Parkinson.
There was a second dismissal of the night when Whitehouse, already on a yellow card and two goals, was sent off for a lunging in on the sideline. This somewhat took the icing off the cake, but United's passage through to the final was virtually sealed.
Villa did have the chance to pull one back from the penalty spot, though, when Maguire fouled Carruthers in the box. Carruthers took the spot-kick himself but failed to claim a consolation after blazing over George Long's crossbar. United's Martin struck the post from a tight angle with just seconds remaining.
Notable performances from the night included Harry Maguire and George Long. Maguire, a stocky centre-back, won every header he went for, he's commanding and has a bright future ahead of him, there's no doubt.
As for George Long, the young goalkeeper, he didn't really have to make a save and was superb too. He commanded his box terrifically and took the danger away from his defenders with some superb catches and punches.
United thoroughly deserve their place in the final. All credit to the players, and most off all to John Pemberton.
Well done lads!