I was impressed by Manchester United performance yesterday but the impression is not going to last more unless they team becomes consistent. It is expected that anything that sacks her coach, should do better in the first few matches with the interim coach. This is because the players would actually want to impress the New coach so as to have their place in the squad. But after some time the spirit will drop.
At least this is a very good start for Ruud Van Nistelrooy as Ten Hag's temporary replacement. And indeed, whether it's with him or with a new coach again, Man United really need solid consistency. Yes, consistency in good games, not consistency in bad games. 
Source: Leicester manager Steve Cooper on the Old Trafford atmosphere
but for the Man United vs Leicester City game yesterday, the opposing coach also admitted that the atmosphere was quite different and intimidating. Man United did a very great job at that moment.
Indeed, in the math, not only the front line of Man United who can really be optimal with 5 goals. but their back line is also able to give the best contribution. proven, there are 16 shots and also 7 shots on target attempted by the opponent, but Man United is able to ward it off, and only conceded 1 goal.