The Foxes slumped to a third home defeat in as many games, curtesy of an early Marcus Rashford strike that earned the Red Devils all three points.
Leicester started slowly once again and nearly went a goal down in the opening stages of the game after Rashford headed over a glorious chance.
The Foxes improved in the second half, with an acrobatic attempt by Jamie Vardy and a free-kick by Rachid Ghezzal that drew a top save from David de Gea, representing the most notable chances.
It ultimately ended in defeat for the East Midlands side as the away side continue their great run of form under Ole Gunnar Solskjær, leaving Puel once again frustrated with his side's poor starts to games.
‘At the start we don't believe enough in our quality’
Speaking to Sky Sports, Leicester manager Claude Puel addressed his side’s slow start.
He stated: “It's crazy. At the start we don't believe enough in our quality. Afterwards we play with intent and we can hurt teams like United. But it's a big disappointment because we found good quality in the second half with a lot of chances to come back.
He added: "The first thing is we have to take responsibility. It was not a fantastic start from United either but we didn't take responsibility. We played backwards or laterally without playing forward, without pressing and without putting them under pressure. It's a shame."
'How can we lose this game'
Speaking further to Leicestershire Live, Puel states that his side deserved more than they got from the game.
“The first feeling at the end was a question: “How can we lose this game?” It is a big shame and big disappointment after this game. We have had a lot of chances without finding the good clinical edge. I think we made a bad start again. Perhaps this time we expected too much from this team, I don’t know."
He added: “We had the first good ball to make a good counter attack but often we played too laterally or behind and it was a shame because we often we made the difference in good situations to shoot or cross, and we didn’t take our responsibility."