The young Reds were dominant in Darren Fletcher's first league game as lead coach, having replaced the successful Adam Lawrence over the summer.
They next face Middlesbrough, on Saturday 23 August, at Carrington.
United played with real sharpness on a pristine Finch Farm pitch, and dominated possession from the off.
Captain Amir Ibragimov dictated proceedings, and kept the tempo high. He combined early on with Gabriel and James Overy to create the first opening, which ended with an Overy shot blocked. Gabriel endured the same fate a minute later after a quick one-two with the skipper.