A Stephen Arthurworrey goal in the 67th minute proved the difference between the two teams as the Glovers recorded only their ninth win of the season, and the first under new manager Paul Sturrock.
It took until the 45th minute for the game’s first shot on target when United substitute Jamie Murphy found the gloves of home goalkeeper Artur Krysiak.
Yeovil, whose successive relegations were confirmed at the weekend, were hard-working if not creative, but were happy to watch a number of Blades’ efforts sail harmlessly over.
Kieffer Moore came close for the hosts with a looping header in the 65th minute which fell just wide after Paul Coutts had come close for Sheffield United.
The breakthrough came shortly afterwards when Arthurworrey’s challenge on keeper Mark Howard helped in Byron Webster’s flick-on from Sam Foley’s free-kick.
United almost drew level in the 81st minute when Murphy chipped the ball past Krysiak, only for Arthurworrey to earn his bread at the other end of the pitch by hooking the ball away from the line.
Despite the setback in Somerset United remain fifth in the table and with an eight-point cushion between themselves and seventh-placed Rochdale.