Positive #3: Another clean sheet
Despite Arsenal's brilliance at the back, Arsenal have found clean sheets hard to come by this season, keeping just four in the league so far prior to Wednesday's win.
The Gunners kept another shutout against United as they showed just how incredible their defence can be. David Raya will be especially pleased with a clean sheet, having denied the Red Devils an equaliser when he kept out Matthijs de Ligt's header with a sensational save.
A clean sheet could be pivotal as it helps Arsenal's goal difference as they look to keep up in a title race that could be very close fought come the end of the season.