A goal in either half proved to be the difference, as Dale ended the night in third spot of Group A.
Although Jake Burger had the first shot of the game, which was blocked, it was the visitors who opened the scoring after 11 minutes.
They won the ball high up the pitch, with it falling for highly rated young striker Chido Obi, who slotted home from close range.
Diego Leon, a multi-million-pound summer signing, blazed a shot over from 25 yards, whilst Dale’s Liam Hogan saw a looping header held at the other end.
Former United stopper Tom Myles saved a low effort from Bendito Mantato before the break, whilst two minutes after half-time, his opposite number, William Murdock, held Tyler Smith’s shot from inside the area.
Myles saved further efforts from James Overy and Obi, whilst Dale’s best chance fell to Levi Amantchi in the closing stages.
Jake Burger drilled a ball forward, which took a deflection into the path of the striker, but he fired wide of the target with his right foot and he bore down on goal.
United made certain of the three points in added time, when James Scanlon converted from inside the area after being found by Victor Musa.
Dale’s final group game of the competition takes place next month, when we welcome Everton Under-21s to the Crown Oil Arena on Tuesday 25th November (7pm kick-off).
Dale XI | Myles, East (1’ Burger), Hogan, Adebayo-Rowling (1’ Griffiths), Pettit, Barlow (21’ Amantchi), McBride, Moss, Humbles, Berkoe (46’ Tutonda), Smith (65’ Henderson).
Unused subs | Lillis, Done.
United XI | Murdock, Overy, Devaney © (60’ Mills), Kukonki, Leon (60’ Musa), McAllister (71’ T Fletcher), Mantato, Fitzgerald, Obi (82’ Biancheri), Thwaites (71’ J Fletcher), Scanlon.
Unused subs | Heath, Armer.
Scorers | 11’ Obi, 90+4’ Scanlon.
Attendance | 2,960.