United completed pre-season preparations with a sixth consecutive victory, battling in tough conditions at Eastleigh.
After victories over Stocksbridge Park Steels, Malaga CF, Chesterfield, Rotherham United and Stoke City, the final warm-up game was at the ambitious National League outfit, where goals from Enda Stevens, Daniel Lafferty and Matt Done secured the win.
Boss Chris Wilder used 21 players on a wet night, with only new loan goalkeeper Jamal Blackman playing a full 90 minutes. New signing John Lundstram also made his first appearance in a Blades shirt.
Former Blade Yeates curled wide the first chance but United were soon ahead. On nine minutes, Duffy glided past his marker on the right and put in a low cross for STEVENS to sidefoot home from inside the six-yard box.
The lead was doubled on 14 minutes as LAFFERTY picked up possession 30 yards from goal and drilled home a shot that did not deviate on the path to the bottom corner of Stack's net.
Eastleigh pulled a goal back with their next serious chance on 28 minutes. McCallum and Stearn challenged for a long pass and CONSTABLE slid the ball under Blackman.
United, who lost Duffy to injury, enjoyed a lot of possession around the edge of the home side's area but were unable to add a third until seven minutes into the second half when the outfield personnel had been changed.
Efforts from Freeman and Thomas were blocked but United recycled possession and from a Brooks cross, Clarke challenged to allow DONE to fire into the roof of the net from close range.
McCallum and Constable had opportunities for Eastleigh, whilst a Brooks shot from the edge of the box was steered around a post by Stack. The home side reduced the deficit on 86 minutes when STREVENS squeezed the ball home but United comfortably held on for another deserved victory.
Eastleigh: Stack, Hoyte, Green, Togwell, Johnson, Boyce, Constable, McCallum, Yeates, Stearn, Hollands. Subs: Wood, Taylor, Ijaha, Obileye, McAllister, Read, Strevens.
Blades first half: Blackman, Bennett, Basham, Stearman, Lafferty, Stevens, Fleck, Carruthers, Duffy (Done 37), Lavery, Sharp.
Blades second half: Blackman, Freeman, Brayford, Wright, O'Connell, Thomas, Coutts, Lundstram, Brooks, Clarke, Done.