Manchester United ditched their preseason struggles by smashing Swansea 4-1 at the Liberty Stadium in their opening game of the Premier League season.

Last season's hero Robin van Persie tucked away a double, as did Danny Welbeck, while Swansea's new record signing Wilfried Bony was on target for the hosts with eight minutes to go.

The home side started the game well as United looked sluggish. Michu closed down David de Gea in the seventh minute before Michel Vorm tipped over a venomous volley from Phil Jones at the other end.

Swansea were putting on all the pressure, but United showed that they could threaten at the other end with some dangerous counter-attacks and the breakthrough would finally arrive in the 34th minute. Ryan Giggs lifted a pass over the top which Van Persie brought down on his chest and buried with a superb finish.

Just two minutes later United were celebrating against as Antonio Valencia latched onto the ball at the far post and smacked a low cross in for Welbeck to finish from close range.

United remained calm and composed after the break with Van Persie firing wide before Patrice Evra had a header cleared off the line at a corner.

Wayne Rooney, who started on the bench, came on soon after and he went on a driving run to draw the defenders off