A goal from £7 million forward Bebe knocked Morecambe's second string out of the Lancashire Senior Cup at the Globe Arena on Wednesday night.
The Portuguese wide man's strike on 29 minutes proved enough for Manchester United's Under 21 side to knock Stewart Drummond's charges out at the quarter-final stage.
A visibly bigger and stronger United side made the better start in front of a healthy crowd and should have gone ahead eight minutes in, Federico Macheda beating the offside trap and tricking his way round Andreas Arestidou, only to see his effort blocked on the line by Chris Doyle.
The young Shrimps side, featuring Laurence Wilson, back training with the club after leaving Rotherham, soon found their feet though, Izak Reid firing over when he should have done better after being put in by Alessandra on 11 minutes.
Regular United first-team stopper Anders Lindegaard then blocked a Dan Parkinson effort at the near post as Morecambe showed promise in attack.
But Warren Joyce's visitors always looked a threat going forward and with a quarter of the game gone Arestidou did well to save a low swerving effort from Davide Petrucci before producing an even better save from the resultant corner to tip a hooked Michael Keane effort round the post.
The Red Devils then went ahead just before the half-hour mark, Bebe, who had tricked his way into the Shrimps box before dragging a shot wide 10 minutes prior, made no mistake second time around, making room for himself on the right side of the area to shoot low and hard into the far corner from 12 yards after an excellent initial run.
Macheda nearly doubled his side's lead five minutes before the break, but after outmuscling Doyle on the edge of the area, he saw a low effort from 15 yards pushed round the post by Arestidou.
The visitors controlled the early part of the second half, with The Shrimps thankful Arestidiou was in excellent form between the sticks.
He first tipped a low Ryan Tunnicliffe effort round the post on 52 minutes before producing his best save shortly after, tipping over a rasping Petrucci effort from the edge of the area to keep his side in touch.
The second half lacked the end-to-end nature of the first, with United continuing to press for a second.
Bebe came close to a second on 68 minutes but saw his shot from 12 yards well blocked after good work from Larnel Cole.
The Shrimps pushed for a leveller without really testing Lindegaard as United progressed to the semi-finals.
Morecambe: Arestidou, McGowan, Wilson (Lewis 87), Parrish, Doyle, Bell, Reid, McGee (capt), Alessandra, Naylor, Parkinson (Woods 67). Subs not used: Pybis (GK), Dunleavy, Newton.
Manchester United: Lindegaard, Wootton, Vermijl, Thorpe (Januzaj 67), M Keane, Fornaiser, Bebe (Lawrence 78), Tunnicliffe, Macheda, Petrucci (capt), Cole. Subs not used: McGinty, Sutherland, Veseli.
Referee: Dean Mohareb