A solitary goal was enough to settle this one at Bramall Lane on a night when Boro had Dani Ayala sent-off, lost Aden Flint through injury and lost for the first time in the league this year.
Tony Pulis named the same starting line-up that began against Leeds on Saturday.
Chris Wilder made three changes from the side that threw away a three-goal lead at Villa Park on Friday night. Chris Basham picked up a yellow card in that game and was suspended, Gary Madine dropped to the bench and Jack O’Connell missed out altogether. In came David McGoldrick, Mark Duffy and Martin Cranie.
Before the game, rich applause rang around the ground as football remembered the legend that is Gordon Banks who was born a five-minute drive from here in Abbeydale, in the days when both this ground and Abbeydale Park hosted Yorkshire County Cricket games.
An energetic start saw Jonny Howson through the United half just left of centre until he was dispossessed not far from the edge of the box and United broke, a move that ended with a tame shot from David McGoldrick from inside the box.
It wasn’t long after when Duffy went for goal from 20 yards with an effort that took a flying save from Darren Randolph to keep it out.
On Friday, Billy Sharp scored his 100th goal for the Blades. His first chance tonight he sliced wide.
Dean Henderson, the subject of some criticism that night, was called into action to deal with a Dael Fry cross which came at the end of a determined run down the left, then again to punch away a curling shot from Lewis Wing.
An even game brought another chance for Boro when Aden Flint headed back to Dani Ayala inside the box. His effort carried power, but was always going wide.
Soon after, Flint pulled up sharply after contesting possession with Sharp. He immediately clutched the back of his right leg, tried to run the injury off, but was forced to give best and was replaced by Stewart Downing. He took up a position on the left, with George Friend tucking in tighter to left of the back line.
It took a smart tip-over from Henderson to keep out a well-struck shot from Jordan Hugill despatched from the edge of the box as the game entered the final five minutes of normal time at the end of a first half where clear cut chances were at a premium, the final one falling to Sharp who hit low on the turn inside the box, but straight at Randolph.
A few minutes earlier, United were forced into a change, George Baldock limping off to be replaced by Richard Stearman.
Wilder made another for the start of the second half, replacing Duffy with Madine.
It was Boro with the brighter start though, a firm shot from Downing bringing Henderson into action.
That seemed to spur United into life and when claims for a penalty (for what was alleged a foul on Madine) were waved away, fans and players alike were incensed.
That proved to be the warm-up act as United poured on pressure, won set-pieces and had a goal disallowed for offside.
That pressure eventually told.
United may have been a little lucky to be awarded a free-kick out on their right, but there was nothing lucky about the goal as Oliver Norwood whipped in a wicked free-kick and Richard Stearman powered in a header from inside the six-yard box.
Things got worse just three minutes later when Ayala, already on a yellow card, committed a foul on the edge of the box, was shown a second yellow, followed by a red.
It was a few moments that tested Boro’s resolve – they were not found wanting and nearly drew level when Britt Assombalonga stole a march behind the United rearguard and brought an unconventional but effective save from Henderson.
Fight as they might, it proved an insurmountable task on the night.
Scorer Stearman 61
United: Henderson, Cranie, Egan, Baldock (Stearman 44), Duffy (Madine 46), Norwood (Capt. from 87), Fleck, Stevens, Dowell, Sharp (Capt. to 87) (Coutts 87), McGoldrick. Subs: Moore (gk); Lundstram, Hogan, Bryan.
Boro: Randolph, Shotton, Ayala, Flint (Downing 34), Fry, Friend (Capt.), Mikel, Howson (La Parra 81), Saville (Assombalonga 67), Wing, Hugill. Subs: Dimi, Clayton, Besic, Fletcher.
Referee: Andy Woolmer. Northamptonshire
Red Card Ayala 57 and 64, fouls
United Norwood 38, foul
Boro Shotton 35, foul
Attendance: 24,805 (1,244 Boro)