Nigel Clough says he sensed his players believed a cup upset was on the cards more than 24 hours prior to the fantastic 2-1 success at Villa Park on Saturday.
Despite the hectic festive schedule, which ended in defeat at Walsall on New Year's Day, Clough has revealed the players trained with a real spring in their step at St George's Park en route to Aston Villa.
The Gaffer remarked: "The training on Friday afternoon showed me the boys fancied causing an upset and they didn't disappoint.
"As a team we have to use the confidence this result will bring for the rest of the season."
The Blades boss dedicated the weekend's win to more than 5,500 Unitedites that vocally backed the team throughout against Paul Lambert's Villa, adding:
"The supporters were terrific, as they have been all season, despite not having much to cheer for a number of weeks.
"This result is definitely for them. On Saturday, from the first minute to the last, they backed the lads and it is an old cliché, but they made the difference.
"In the dressing-room the lads were saying that even when you are running on empty, support like that means you find that extra ounce of energy to chase the ball and close down the opposition.
"For me I am just happy we have given them a day to remember, we hope it is the first of many."
Clough also reserved a special word for his young centre-half: "Let's not forget Harry Maguire is still only 20, so what a fantastic experience for him to play at Villa Park and show he can handle someone like Christian Benteke, but, in truth, we didn't have anybody who wasn't at their best on the day."