Rafa Benitez bemoaned a penalty which "changed everything" after seeing his Newcastle United side beaten 3-1 at the Etihad Stadium.
Sergio Aguero scored a perfect hat-trick for the Premier League leaders, while Jacob Murphy scored for Benitez's side.
Aguero's second goal came from the penalty spot after Javier Manquillo was penalised for a push on Raheem Sterling.
United manager Benitez felt the penalty, awarded by referee Paul Tierney, was a "soft".
"I think that we wanted to stay in the game and we did it," said Benitez. "The penalty was a bit soft, and it changed everything.
"After we scored, we had a couple of chances. They are a very good team, our reaction was quite good.
"We changed at the end and played with four at the back. The idea was to stay solid and try to regain and play counter-attack.
"At the beginning, we were giving the ball away easily. To find the balance between defending and attacking is what we were trying to do.
"I have been praising the players the whole season in terms of effort ... sometimes it's a bit of luck.
"If you have a little bit of luck, you can be ahead in some games."