A PERFECTLY-STRUCK free kick by Simon Osborn six minutes from time kept Wolves on course for a First Division play-off spot when Marcelo's tap-in just after the hour seemed to have revived the Blades' faltering thrust for promotion.
But this scrappy game was notable more for sloppy passing, undisciplined tackling and missed opportunities than anything that smacked of Premiership potential and if either of these clubs finds itself back in the top flight they will have to improve significantly to stay there.
It was the third successive match in which United have conceded a late goal, and to increase manager Steve Bruce's problems, the striker Andy Campbell was carried off in the first half after a collision with Kevin Muscat while the full-back Rob Kozluk was sent off four minutes from time for a second bookable offence. Kozluk was in good company - five other United names and two from Wolves also went into the referee's notebook.
Both defences began by lulling their supporters into a sense of insecurity. The Blades allowed Havard Flo, cousin of their former striker Jostein, a free header in their first minute which he directed over the crossbar and the Wolves centre back Dean Richards survived an appeal for a penalty after Lee Morris's shot appeared to strike his hand.
Flo headed a corner narrowly wide and the United international goalkeeper, Alan Kelly, justified his return to the side with two excellent saves, first from Muscat's 20-yard drive and then after Osborn had released Carl Robinson on a run into the penalty area.
However, hopes of a holiday goal glut soon faded in a flurry of mishit passes and even poorer finishing. Marcelo's miss-kick fell to Campbell on the Wolves goalline but he missed the ball completely, while at the other end Flo shot into the side netting when Osborn was perfectly placed.
Then Morris crossed from the left, the substitute Petr Katchouro dummied and Marcelo tapped in to give the Blades the lead after 62 minutes. It was the Brazilian's 17th goal of the season.
Wolves left it late to preserve their record of only one defeat since Boxing Day. Steve Corica was well inside the penalty area when the substitute was bundled off the ball, but the referee awarded a free-kick just outside the box and Osborn gave Kelly no chance with a perfectly flighted shot into the top corner. Perhaps it was just as well the referee did not award a penalty - on the evidence of what had gone before, Wolves would probably have missed it.
Sheffield United (4-4-2): Kelly; Kozluk, Tebily, Sandford, Quinn; Morris (Derry, 85), Woodhouse (Jacobsen, 89) Devlin, Hunt; Campbell (Katchouro, 40), Marcelo.
Wolverhampton Wanderers (3-5-2): Stowell; Richards, Curle, Emblen; Muscat, Robinson, Osborn, Sedgley, Gilkes; Flo, Connolly (Corica, 82). Substitutes not used: Simpson, Naylor.
Referee: R Styles (Waterlooville).Reuse content