The Reds leave Bramall Lane empty-handed after hot-tempered clash.
Billy Sharp's early strike proved enough here in S2 as the Blades defeated the Reds to leave Barnsley still without a point on their travels this season.
Reds Gaffer Paul Heckingbottom kept an unchanged lineup for the third straight game, but Mamadou Thiam was among the substitutes.
The hosts began brightest, Sharp was denied by Adam Davies point blank following a cross by Enda Stevens from the left. It was a fine save by the Reds stopper.
On 11 minutes Barnsley broke on United at pace before Adam Hammill fired a shot wide of the Blades goal.
United were dominant in the early stages and on 17 minutes they took a deserved lead...
Again it was Stevens down the left and he crossed low unopposed, the ball fell perfectly for Sharp who this time made no mistake, firing powerfully beyond the despairing dive of Davies.
The game died down in terms of entertainment from then on, but on 42 minutes an off-the-ball incident between Angus MacDonald and Blades striker Leon Clarke resulted in both men being dismissed.
HALF TIME: Sheff Utd 1-0 Barnsley
Heckingbottom replaced the ineffective George Moncur and Jason McCarthy with Ike Ugbo and Ethan Pinnock, with the Reds moving to two up front, and three at the back.
The bookings kept on coming, with Matty Pearson and United's John Fleck going into the referee's notebook.
A couple of Hammill corners on the hour mark caused problems; Brad Potts headed over at the near post, then Tom Bradshaw nearly got in ahead of the 'keeper after Pearson's header back across goal.
On 70 minutes the Reds somehow lived to fight on...
A slipped ball into the six-yard box was stabbed goalwards but somehow Davies kept it out with a combination of legs, knees and hands, then watched as the ball rolled across the goalline.
Davies then reacted quickly to tip over a Jack O'Connell header from a corner.
Mamadou Thiam made his Reds bow, replacing Bradshaw on 79 minutes.
Barnsley saw more of the ball as the game drew to a close, crosses were sent into the box, shots were fired in but United defended manfully and stopped the Reds carving out a clear-cut opportunity.
FULL TIME: Sheff Utd 1-0 Barnsley
Reds XI: Davies (GK); McCarthy (Pinnock 45'), MacDonald, Jackson, Pearson; Williams; Moncur (Ugbo 45'), Potts; Hammill, Bradshaw (Thiam 79'), Hedges.
Unused subs: Townsend (GK), Mowatt, Barnes, Bird.
Booked: McCarthy (30), Hammill (45), Pearson (48).
Sent off: MacDonald (42).
