In as much as Manchester united took all 3 points i still wouldn't consider this win as a big win because Leicester city is a relegation bound team with less motivation and at such do not really stand any chance of winning any game at the moment, they have not recorded any win at the moment and seemed not to be capable of withstanding Manchester united who are also struggling to move up the table. However, Manchester united on the other hand are making some incredible progress at the moment and have recorded some important wins which has directly imparted the team in all ramification.
You may not consider the game as a big win for Manchester Unitd but for me it was a significant win, regardless of Leicester City strength. A win is a win, this victory could serve as a confidence booster for Manchester United. Hopefully they can build on this momentum to salvage their season. Luck may be on their side and they can go all the way to win the Europa League title to secure a champions league football next season.