New manager Loius Van Gaal only needed his first game in charge to deliver a 7 goal thriller for the fans to celebrate and also provided the opportunity for the fans to see their new signings on display against the MLS side LA Galaxy.
Van Gaal opted to start the match with three centre-backs – Chris Smalling, Jonny Evans and Phil Jones – while Antonio Valencia and teenage debutant Luke Shaw were used as wingbacks, with first-choice keeper David De Gea in goal.
Another summer signing, Ander Herrera, also made his debut in midfield alongside Darren Fletcher while Juan Mata, Rooney and Welbeck started in a 3-5-2 formation.
Mata twice went close early on before he set up Welbeck to fire in a spectacular opener from 25 yards.
That was the way it remained until three minutes before the break when Rooney added a second from the penalty spot after AJ Delagarza had handled Valencia's cross into the box.
And in first-half injury time, Rooney netted his second and United's third with a simple finish from Welbeck's cross.
Van Gaal made his second major decision as United manager which payed off as he made nine changes at the break bringing on Anders Lindegaard, Rafael, Michael Keane, Tyler Blackett, James, Shinji Kagawa, Tom Cleverley, Nani and Ashley Young.
Just after the hour mark, 20-year-old James side-footed the fourth from Young’s low cross with three more goals arriving in the final seven minutes, James netting his second of the game on the rebound after Young’s initial strike had been saved.
It was 6-0 on 88 when Young surprised even himself by collecting Herrera's assist to round the keeper and score from a tight angle and the under fire winger was at it again minutes later as he latched onto Rafael's pass.
Speaking after the game Lois Van Gaal praised his players performance stating that " I don't have to restore a mentality because what I have seen in the first week, they have a mentality. If we progress like this, we can be the next champion". On the fine display of 20 year old James Reece he was quoted saying "When you listen, you can play good. He is a young boy with a lot of talent + I hope he can perform like this again."
Though this may only be a friendly game, but it offers something of a kind of relief and optimism for millions of fans worldwide who watched as their club almost crumbled under the managerial reign of Former Everton Boss David Moyes loosing out of European football for the first time in almost 16 years.
United next pre season game comes up on Saturday 26th of July against AS Roma in Denver.