Jonny Evans claimed the first goal of his Manchester United career as the champions took control of their trip to Wolverhampton Wanderers at the break.
To make matters worse for hosting Wolves, they ended the half a man light following Ronald Zubar's second caution.
In a first half of very few clear goalscoring chances, United broke the deadlock in the 21st minute. Wayne Rooney's corner was squared by Michael Carrick into the path of Evans, who had fired past Wayne Hennessey from close range.
Zubar's first booking of the half arrived moments later when he failed to win the ball in a challenge with Rooney.
He was then handed his marching orders in the 39th minute following a mistimed tackle on Danny Welbeck.
United made their numerical advantage count in the 43rd minute by claiming their second goal of the afternoon. Rooney released Antonio Valencia inside United's half, before the Ecuadorian broke clear to slot past Hennessey from a narrow angle.
There was still time for United to add a third in stoppage time when Welbeck converted Valencia's cross from 12 yards out.
As it stands, United are four points clear at the top of the Premier League table, while Wolves are bottom.
