PASADENA, Calif. – The LA Galaxy expected to see Manchester United at their best, or whatever their "best" might be in their preseason opener. They hoped to give the English powerhouse a real test.

Not all went as expected in Wednesday night's Rose Bowl friendly. Man. United were impressive in Louis van Gaal's debut as manager, but the Galaxy weren't much opposition in front of 86,432 mostly red-clad fans, a group that included David Beckham, who starred for both clubs.

Danny Welbeck scored on a superb blast off the post in the 13th minute, Wayne Rooney added two goals at the close of the first half, Reece James and Ashley Young each netted two more in the second half, and the Red Devils opened their US tour with a 7-0 demolition of LA.

It was just the Galaxy's second loss in five completed friendlies against English opposition – the other defeat was to Chelsea in Beckham's 2007 club debut – and dropped their record against European foes to 8-14-6. The margin of defeat was LA's worst in an exhibition by three goals.

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Center back Omar Gonzalez, who had hoped to get a few minutes as he returns from an ankle injury sustained during the World Cup, was on the bench but didn't see action, and head coach Bruce Arena fielded 23 players, none for much more than an hour. Rookie defender Kyle Venter departed with an injury shortly after coming on in the second half.

Manchester United, their players looking to impress van Gaal as they battle for jobs ahead of the Aug. 16 English Premier League openers, played with vigor and dictated terms most of the way. Attacking midfielders Juan Mata, who assisted Welback's goal, and newcomer Ander Herrera had immense influence and Antonio Valencia was dangerous on the right flank.

Galaxy goalkeeper Jaime Penedo made two big early saves to keep the score level, tipping a 33-yard Herrera blast over his crossbar in the fifth minute and getting to the ground to scoop up Welbeck's shot from the top of the box three minutes later.

Welbeck scored five minutes after that, finishing from 28 yards after Mata dispossessed A.J. DeLaGarza, first-timing a square pass past a diving Penedo, off the left post and into the net.

Defensive miscues cost LA heavily at the end of the half.

DeLaGarza handled the ball in the area while sliding to block a Valencia cross on the right byline in the 41st minute, and Rooney converted the penalty kick.

Rooney netted his second just as stoppage-time began, when center back Tommy Meyer, under no real pressure, whiffed on a low pass from Valencia, leaving the striker one-on-one with Penedo. The Panamanian got a piece of the ball but couldn't control it, and Rooney was able to walk the ball into the net.

Both teams made wholesale changes in the second half, but United continued to press the action. James, a halftime substitute, slotted a pass through the box from Young in the 62nd minute and scored on a rebound after Galaxy goalkeeper Brian Rowe came off his line to stuff a Young shot in the 84th. Young scored on an empty net in the 88th, after Rowe came out of his box to try to cut off a through ball, and beat Rowe again in the 90th from Herrera's feed.

The Galaxy put just two shots on frame and came to close to scoring just once, on Gyasi Zardes' volley from the top of the box off a Stefan Ishizaki feed that forced a save from goalkeeper David de Gea.