First-half goals from Jadon Sancho, Fred and Anthony Martial did the damage in Bangkok’s Rajamangala Stadium, and Facundo Pellistri rounded off an eye-catching United victory late on, as both sides made wholesale changes.
Liverpool used 32 players in all, changing all 10 outfield players every half hour. The Reds gave debuts to both Fabio Carvalho and Darwin Nunez, the new £85 million ($100m) signing from Benfica, who played the final 30 minutes.
United, meanwhile, handed Tyrell Malacia his first run out, the new left-back playing 45 minutes following his switch from Feyenoord, with both sides using a host of academy players alongside their established first-team stars.