Marouane Fellaini's stoppage-time header spoiled Arsene Wenger's final trip to Old Trafford as Arsenal manager as his looping header ensured Wenger's side remain without an away Premier League point in 2018.
Arsenal paraded their youngest starting eleven in this fixture since the side that got thumped 8-2 by United in 2011 and they performed admirably, responding magnificently to Paul Pogba's 16th-minute opener - with Henrikh Mkhitaryan equalizing early in the second half.
But, there were lessons to take from the somewhat friendly encounter at Old Trafford on Sunday.
Pogba magnificent in preferred position, again
Paul Pogba has demonstrated yet again to Jose Mourinho with a brilliant performance that he is not the kind of midfielder designed for the dirty jobs. Rather, he enjoys that position just on the left of United's midfield, that allows him more impetus to surge forward to create and score goals, leaving most of those takes for Ander Herrera and Nemanja Matic.
Against City, the French star spearheaded a sensational Manchester United comeback, scoring twice in the game. He provided a sumptuous assist for Romelu Lukaku against Bournemouth. Pogba outmuscled Mousa Dembele on the left-wing to pick out Alexis Sanchez with an inch-perfect cross to hand United an equalizer against Spurs in the FA Cup semi-final. And on Sunday, he orchestrated an attacking move for United against Arsenal, before finishing calmly past David Ospina in goal for Arsenal after an initial Alexis Sanchez's effort was rebuffed by Hector Bellerin.
United still need to sort Sanchez's rightful position at the club, as he hasn't been consistent with his performances on the left of United's attack, making starting spots for Anthony Martial and Marcus Rashford difficult to attain these days. But, Pogba has definitely settled the lingering issue with Jose Mourinho on where and how to play in United's midfield. He must keep it up.
United must be more ruthless
City already Premier League champions this season went to West Ham in a game played just before the United v Arsenal game and scored four. That's a team that have the Premier League in their locker already.
But United had to rely on a stoppage-time header from Fellaini to secure a win at home against a second-string Arsenal side.
United pulled a superb performance in the second half against City at the Etihad to win 3-2 from two goals down, only to fall to a 1-0 defeat vs 20th-placed West Brom at Old Trafford the following week. That has been United's story this season. United haven't been ruthless in front of goal and have lacked consistency in their performances.
City will definitely improve their squad in the summer and you will expect Liverpool (scoring freely) to do so also. If United don't change their cautious approach and become more ruthless in front of goal, it will be difficult for the Red Devils to mount a serious title challenge next season.
Chelsea won the league last season scoring a mammoth 85 goals winning 30 games in the process, while City have already scored 102 goals winning the same amount of games (30) as things stand. United need to become a ruthless side in front of goal and have to be consistent with their performances to seriously mount any title challenge next season.