They also boasted an unbeaten Premier League record under Ole Gunnar Solskjaer, but the Norwegian was to suffer his first domestic setback during a forgettable afternoon in north London.
Granit Xhaka surprised David de Gea with an early strike which deceived the United goalkeeper, while Pierre-Emerick Aubameyang doubled the Gunners’ advantage from the penalty spot.
Young is not convinced that he should have been given that opportunity, with Alexandre Lacazette taking a rather theatrical tumble after coming into contract with Fred inside the box.
“From where I was I don't think it's a penalty,” the United captain told BBC Sport.
Young added on the Red Devils’ performance as a whole, with Romelu Lukaku missing a number of chances that he would have snapped up on another day: “Disappointing, especially when you create so many chances.
“On another day we take those chances and we could be two or three up at half-time. Against top teams you get punished.”
Defeat against a fellow top-four hopeful has dropped United out of the Champions League places.
They now sit fifth in the Premier League table, two points behind Arsenal and three adrift of Tottenham.
While frustrated to have suffered a setback on the road, Young believes there is plenty of cause of positivity in the Red Devils camp.
A testing start to the season under Jose Mourinho had left them well off the pace and facing up to the threat of a humbling finish well behind the race for a Champions League spot.
To now be very much in the hunt shows have far the club have come in a short space of time, with Young adding: “I know the character and team spirit we have.
“We've turned things around - where we were in October we'd have taken where we are now, but as a club we should be pushing higher up the league.”