United's dismal luck away from home continued on the long trip to Crystal Palace.
Alan Lee's first half goal ensured that United are still waiting for an away win in 2010.
Under Paul Hart, Palace looked revitalised and the Blades took the brunt of the new-manager syndrome.
Quinn returned to the starting XI, replacing frontman Camara, who dropped to the bench, which gave boss Blackwell the option of either 4-4-2 or 4-5-1 systems. New Palace boss named former Blade Derry as his captain after the midfielder shook off a back problem.
Wearing black shirts, white shorts and socks, it did not take long to establish that United would play with Ward and Cresswell in attack, although the visitors could not repeat the impressive start of the previous week.
Ambrose, Palace's top scorer this season, was prominent in the early play. He had a free-kick blocked and then almost took advantage when Nosworthy's back-pass hit Bartley, but the young loanee quickly recovered.
The home team's defence also displayed a lack of cohesion on a number of occasions in the opening 15 minutes but Speroni was not totally exposed and Palace survived when Ward was adjudged offside following Cresswell's probing.
It was Palace, though, who grasped the advantage at the halfway point in the half. A deep cross by Butterfield from the right dissected the Blades defence and LEE edged in front of Morgan to divert the ball beyond Bunn from close range.
Bunn needed treatment moments later and was fit to continue but United were struggling to find a rhythm, particularly with Ward and Cresswell not getting any change out of Hill and Davis. Quinn was busy in the midfield and the visiting side's best chance of the first half was following a rare free-kick award on 41 minutes. From a Yeates delivery, Ward added a flick at the front post and Speroni just gathered before Cresswell arrived.
Three minutes of stoppage time was announced and both sides finished the half with ten men. Both Bartley and Lee trotted off down the tunnel early to receive treatment after a clash of heads.
Bartley and Lee reappeared for the second period, both sporting bandages covering their head wounds, but the first notable action after the break was a booking for Derry, for a tackle from behind on Cresswell.
The best opportunities in the early part of the second half fell for the home side. Ambrose anticipated Derry's header but the winger couldn't beat Bunn and then Lee lifted the ball over the top after Carle's cross had evaded everyone and reached the back post.
Camara was introduced with more than half hour to go, at the expense of Quinn with Ward moving to a wide role. The referee's failure to spot Lee's elbow on Montgomery was the catalyst for a number of flashpoints which resulted in Davis, Bartley and Williamson cautioned in the space of a few minutes.
Andrew headed over an Ambrose free-kick for the home side and a frustrated Williamson was withdrawn with 20 minutes to go, Harper taking over in the heart of the midfield.
The last contribution of Yeates, who was replaced by Evans soon after, was to swing in a cross which Derry headed into his goalkeeper's arms, but United were on the front foot going into the final ten minutes.
Bunn did well to hold a long-range free-kick from Ambrose whilst the Blades poured forward and drilled balls into the box late on. Palace did all they could to frustrate the visitors late on, including wasting time with substitutions and N'Diaye picking up a booking.
Camara lashed a shot wide in the last minute of normal time and Evans saw an effort blocked and other drift wide. Bartley and Morgan both spent more time in Palace's box than their own late on but United were unable to claw back that all-important equaliser.
Palace: Speroni, Clyne, Hill, Derry, Ambrose (Hills 90), Carle (Scannell 90), Andrew (N'Diaye 87), Lee, Butterfield, Ertl, Davis.
Unused: John, Lawrence, Djilali, Mann.
Blades: Bunn, Montgomery, Morgan, Nosworthy, Yeates (Evans 78), Williamson (Harper 70), Cresswell, Ward, Bartley, Quinn (Camara 58), Kallio.
Unused: Bennett, Taylor, Stewart, Seip.
