United's automatic promotion hopes suffered a huge blow with a home defeat to Fleetwood Town.
First half goals from Josh Morris and Nick Haughton gave Fleetwood a major advantage and despite Matt Done's goals and immense pressure, the Blades were unable to rescue a point or more.
New signing Steven Davies was thrown straight into the starting line-up for the encounter. Signed on loan from Blackpool on Friday, Davies partnered Done in attack. Baxter also returned to the starting XI following his three-match suspension.
The Blades began with a 4-4-2 formation, with Coutts switching to a wide right role to accommodate Baxter, who slotted in alongside captain Doyle. The early endeavour was from United and the first chance arrived on five minutes but an under pressure Davies headed Murphy's cross wide.
Davies blasted over following a mistake in the Fleetwood rearguard and former Blades defender Jordan hobbled off after 11 minutes. United's early dominance continued and from another Murphy cross, Schumacher slammed the ball against his own goalkeeper, resulting in a corner, and Baxter nicked possession in midfield, drove at the defence before shooting over.
But, against the run of play, Fleetwood netted with their first serious foray into United's half. On 25 minutes, Proctor used the space afforded to him to lay off to MORRIS, who beat Turner at the near post from 20 yards.
Coutts volleyed over a Blades corner but there was another shock just around the corner. Basham's tenth booking presented HAUGHTON with a free-kick and although his first effort was blocked by the wall, he caught Turner out at the near post with the rebound.
Bramall Lane was shocked but the Blades hit back. A short corner saw Murphy deliver and Doyle's header was tipped over but the arrears were halved with the next set-piece. Baxter delivered, Basham won the initial header and DONE touched home from close range.
From another quick corner, a Harris cross was diverted wide by Basham but Fleetwood had a good chance to regain their two goal advantage in injury-time at the end of the first half when Harris squandered possession but McEveley, who was booked moments later, crowded out Proctor.
The Blades began the second half with an increased tempo and were appealing for a penalty after 30 seconds but the challenge from Roberts on Done from Brayford's cross failed to attract the attention of the referee.
Baxter fired wide with a first time effort and the corner count was adding up, as was the bookings for visitors as they attempted to stop the Blades by any means possible.
On 63 minutes another appeal for a penalty was waved away by referee Deadman, despite Murphy falling up McLaughlin's challenge, whilst Clough's first change was Adams for Baxter.
With the final 15 minutes approaching, United went close again. From a Harris cross, Adams headed back into the danger area but Doyle's effort from eight yards was tipped over by Maxwell.
The tiring Davies was replaced by McNulty for the final onslaught and the he went close with a shot from the edge of the box. Adams had an effort blocked and Wallace was introduced for the final moments.
Expectedly, Fleetwood's efforts to run down the clock continued in the closing moments, which was recognised by the referee as he added six extra minutes. Done headed wide a Murphy cross but the Blades were unable to create another chance worthy of testing Maxwell before slipping to a second consecutive defeat.
Blades: Turner, Harris (K. Wallace 86), Brayford, Basham, Doyle, Murphy, Baxter (Adams 69), Done, Coutts, McEveley, S. Davies (McNulty 79).
Unused: Alcock, Willis, B. Davies, Reed.
Fleetwood: Maxwell, McLaughlin, Murdoch, Roberts, Evans, Schumacher, Morris (Crainey 84), Chicksen, Proctor, Jordan (Pond 11), Haughton (Dobbie 77).
Unused: Ball, McAlinden, Hunter, Springthorpe.