A combination of woeful, undisciplined defending at set-plays and a lack of organisation to counter Antonio Valencia's superiority on Manchester United's right was crucial to this demoralising defeat for Wolverhampton Wanderers. Clubs in the lowest reaches of the Premier League must have sighed with relief because a continuation of this level of performance would guarantee Wolves one of the relegation places.

United, returning from their beating in Bilbao, began sluggishly and finished haphazardly by their standards. In between they blitzed a disheartened Wolves team who lacked both leadership and any inspiration on the field. Roland Zubar's dismissal was a contributory factor and United had started by passing the ball around comfortably but slowly, evidence perhaps of their tiredness. But Wolves could not play at a pace to exploit this lethargy and only a Steven Fletcher header from a Matt Jarvis cross threatened David de Gea.

Wolves, shorn of the passing of Jamie O'Hara and the attritional qualities of Karl Henry, played the ball square and backwards with Fletcher as a lone target. Terry Corner moved Kevin Doyle closer after the first 15 minutes but any chance of unsettling United was undone when Zubar's recklessness reduced his team to 10 men.

Sir Alex Ferguson had started with a quartet of forwards, maybe visualising a goal feast. The four lacked co-ordination early on. However, Valencia, returning on the right, ran free and with pace beyond and across Stephen Ward who left him virtually unchallenged at times. With Wayne Rooney and Javier Hernández occupying Richard Stearman and Sébastien Bassong, it was difficult for either to take covering positions to help the beleaguered left-back.

Paul Scholes and Michael Carrick had the most comfortable of afternoons feeding the Ecuadorian. Ward had little help from in front either where Wolves failed to disturb the supply. Jonny Evans's excellent long crossfield ball, for example, was not challenged. The winger controlled easily and progressed towards goal.

Regardless of the contrast in the sides' technical ability, there is no excuse for failing to mark tight and challenge at set pieces. Ronald Zubar allowed Carrick to drift behind him and his free header gave Evans his first United goal. Without direction and discipline Wolves defended feebly at set-plays. A second-half short corner was equally disastrous and Hernández was left free to head in as three defenders stood watching as Kevin Foley lost his man.

It is vital if defending man-for-man in the box that when the ball is played the marking player can see both the ball and the man he has been designated to mark. To do this he has to be on the half-turn, not square on, and not allow his opponent to drift free.

With 10 men Wolves passed in midfield without any hint of threat, leaving Fletcher upfront engaged in a hopeless task. In Wolves' predicament they must sacrifice some principles, go direct and keep forwards on and up the field. A gamble of 3-3-3 after Zubar's dismissal would have been a brave option and they could have tried to bypass midfield, playing narrow and hitting targets upfield.

The game developed into a slow painful ending for Terry Connor's men as United tried to walk the ball into the net. Being 3-0 down at half-time and with only 10 men is a baptism of fear and helplessness; only the final whistle provides relief. But in the second half Wolves lack of tactical change and continued poor discipline at corners and free-kicks only worsened their nightmare.

• This article was amended on 19 March 2012. The original referred to Antonio Valencia as Colombian. This has been corrected.