Anthony Martial scored an impressive goal on his debut as Manchester United recorded a morale-boosting 3-1 Premier League win over rivals Liverpool at Old Trafford.
Daley Blind opened the scoring early in the second half and then saved his side at the other end with a tremendous goal-line clearance before Ander Herrera won and converted a penalty to put the hosts two up.
David de Gea, who signed a new contract this week, could do nothing to stop a stunning Christian Benteke overhead kick on his return to the starting line-up following the collapse of his move to Real Madrid before new signing Martial marked his debut by coming off the substitutes' bench to seal the points with an excellent solo goal.
The result meant United inflicted a second consecutive loss on Liverpool, while Louis van Gaal's side move up to second in the early-season table.
Poor control from Fellaini meant the rare opportunities United had in Liverpool's area came to nothing, while Liverpool struggled to provide their lone striker, Benteke, with any kind of meaningful service as neither side registered a shot on target in the first half.
Mata took it, cleverly cutting a pass back to the 18-yard line where an onrushing Blind was unmarked. The centre-back took full advantage of the space, curling a sumptuous left-footed strike into the top corner.
A timely intervention from Chris Smalling gave United a let-off after De Gea's scuffed clearance had presented Liverpool with a rare opening at the other end before the Spain goalkeeper made amends with a sprawling stop to divert Danny Ings' bouncing effort away from goal after a free-kick had deflected into the forward's path.
Brendan Rodgers' side were starting to become more threatening and Blind had to make two frantic clearances from the goal-line after Martin Skrtel had headed on a James Milner corner to cause a mad scramble.
But those hopes were dashed when Martial went on an excellent solo run, beating Skrtel and converting a cool finish into the far corner to mark his debut in style.
