United made an electric start to the new term, surging forwards in waves through Bryan Mbeumo on the right, Patrick Chinazaekpere Dorgu on the left and Mason Mount and Matheus Cunha through the middle.
But it was the Gunners who took the lead, courtesy of a point-blank-range header from Riccardo Calafiori, after Altay Bayindir directed a Declan Rice corner towards his own back post under pressure from William Saliba.
The Reds asked plenty of questions in the second half, through the likes of Mbeumo and substitute Amad in particular, but, despite deserving something from the game on balance, we couldn't breach the Gunners' defence on the day.