West Ham manager Manuel Pellegrini has criticised Man City's use of 'tactical fouls' after Pep Guardiola's side got their Premier League title defence underway in perfect fashion.
City responded to Liverpool's 4-1 victory over Norwich on Friday evening with a faultless 5-0 demolition of West Ham at the London Stadium, with a Raheem Sterling hat-trick, as well as goals from Gabriel Jesus and Sergio Aguero.
But speaking after the game, Pellegrini said City repeatedly fouled his team when they were on the attack, and admitted the Hammers had been naive at the other end of the field.
He said: "As a manager it is difficult to say you are not happy in the way we worked, especially with how we played in the first 45 minutes.
"There was not a lot of difference between the two teams.
"Last season we lost 4-0 here to Man City and we knew they could score more. This time, in the first 45 minutes we played well, we didn't ever feel on the bench that City could score. We had good possession, maybe we needed a couple of more players to get in their box but it was a tight game.
"Every time that we tried to arrive to their box, they committed 13 fouls. We had just five. We were a little bit innocent. After that we had a couple of chances to make it 2-1, finally with spaces in the last minutes the scored their goals."
Pellegrini seemed to suggest that City use tactical fouls "as a system" - a criticise that has been levelled at Guardiola's team in the past.
He added: "We must be more intelligent though to know when to make them, not use it as a system.
"If you review the game today, we didn't create too many chances because many of our attacking chances were stopped by a foul. They had 13 fouls, we had five fouls.
"But I repeat, I don't think that is just the reason we lost 5-0."
City have come under fire previously for their use of fouling to prevent opposition attacks.
Last year, Guardiola responded angrily to Manchester United boss Ole Gunnar Solskjaer after the Norwegian mentioned their use of tactical fouling.
Others, such as Jose Mourinho, Martin Keown and Gary Neville, have also repeatedly pointed out Guardiola's use of the system.
