Jose Mourinho's reshaped Manchester United destroyed Premier League champions Leicester City 4-1 with a performance that thrilled Old Trafford and justified his decision to leave out Wayne Rooney.
The shake-up seemed to liberate Paul Pogba, who led the way with a polished display, heading his first goal for the club on 42 minutes and starting the clever move that led to Juan Mata firing home United's second after 37 minutes.
Chris Smalling had begun the rout with a header after 22 minutes, while Mata also played a major part in United's third, firing across goal for Marcus Rashford to convert from close range.
Three of the goals came via Daley Blind corners from the left as champions Leicester headed for their third league defeat.
Claudio Ranieri responded at the interval by replacing Jamie Vardy and Riyad Mahrez.
The decision paid off, somewhat, as substitute Demarai Gray's looping 20-yard shot flew over David de Gea for a 59th-minute consolation.
Speaking about Rooney, who was dropped to the bench, Mourinho said: "He's a big player for me, a big player for United, a big player for this country.
"He's my man, I trust him completely. He's as happy as I am at this moment and that's the team.
"It was a very good performance. It's obviously a very good result, it's not easy to win against them and even more difficult to win in such a comfortable way.
"I think the team played very well, you score four goals, and the striker doesn't score a goal and I think the striker plays phenomenal.
"(Zlatan Ibrahimovic) Ibra played absolutely incredible in the way he started our pressure. My team as a team played very well."
Leicester boss Claudio Ranieri was mystified as to how his side were on the end of such a heavy defeat after a promising start.
He told Sky Sports: "It's unbelievable what happened because we started very well and for the first 20 minutes it was our match.
"We put pressure on, we pressed very well, we tried to create chances but suddenly we switched off.
"We are very solid on corners and free-kicks. It's difficult to score against us, but today it was very strange for us.
"It's not possible to concede three goals off corners, that means you are not concentrating."
Ranieri also gave his reasons for substituting Jamie Vardy and Riyad Mahrez at half-time, saying: "At that time, the match was gone. I preferred to reserve them for the next game against Porto on Tuesday."
