The Red Devils eased into an eighth-minute lead thanks to United captain Wayne Rooney’s header from Ashley Young’s corner in front of 68,414 at Levi’s Stadium.
Louis van Gaal’s men doubled their lead through Jesse Lingard and Belgium international Adnan Januzaj added before Rafinha netted a late volley.
And United midfielder Mata praised his Red Devils team-mates after three successive victories on their tour of the United States so far.
Mata posted the above snap and wrote on Instagram: “Good game boys, three out of three. @manchesterunited #MUtour”
Netherlands winger Memphis Depay, who moved to Old Trafford from PSV Eindhoven in a £25m deal earlier this summer, is already thinking about their final game against Paris Saint-Germain.
Depay wrote: “Good result against Barcelona PSG next.”
Finally, United youngster Januzaj reflects on his strike against the reigning La Liga, Copa del Rey and Champions League holders.
Januzaj uploaded the below snap and posted the following caption: “Very happy with the result today! Great team effort and always good to get a goal #MUtour”
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