These sides will have to do it all again in a fortnight and United will have to improve massively if they're to make it through to the next stage for the first time since 2006.
How was Nabil Bentaleb on debut? Who performed will and who let their standards slip? Liam Kennedy has his say...
5. DeAndre Yedlin - 5
A willing runner but never really involved enough down the right as United failed to stretch the opposition. Photo: Ian MacNicol
6. Sean Longstaff - 4
An awful, awful day for the midfielder. One of those games where everything he touched went to the opposition. Photo: Ian MacNicol
7. Nabil Bentaleb - 4
You could tell he had not played for quite some time. A bright opening 20, but a fair few hospital passes after that. Looks a million miles off the pace. Photo: Serena Taylor
8. Miguel Almiron - 5
Had an excellent opportunity to win it for United but his acrobatics could not salvage anything. Photo: Gareth Copley