The Citizens took control with two quick first-half goals, the first arriving on 31 minutes when Ruben Dias’ long-range strike deflected off Dan Ballard and beat Robin Roefs.
Josko Gvardiol doubled the lead before Phil Foden sealed the win in the second half with a powerful header off the crossbar.
“It was a good experience because it is tough to repeat high performances at this level,” said Le Bris.
“We knew before the game the sequence of fixtures we faced. Liverpool away, Manchester City away is a strong sequence.
“We did well against Liverpool but we weren’t at our best today. Manchester City were relentless and they deserved the win.
“Tactically we were well organised (in the first 30 minutes) but it wasn’t enough. Individually it was possible to escape the pressure but we didn’t.
“We didn’t take those opportunities and they got progressively closer and closer to our goal and finally a shot made the difference.
“When you play with a deep block, shooting from mid-distance is a good idea and they found a solution.”