The final question for Roberto Mancini, long after the stadium had cleared, was this: had he been serious when he talked before the match of Chelsea winning the Premier League with something to spare, or was it part of a subtle plan to get into the opposition's mindset?

A smile flickered across Mancini's lips. "There used to be a manager in Italy who would do that," he said. "Every week he would say the opponents were fantastic before they played."

The man he was referring to was Nils Liedholm, a Swede who managed for nearly four decades in Italy, with the distinction of being known as Il Barone. And Mancini? "I was being serious," he said. "Chelsea are the best team in the league, just like I said."

There is a weight of recent evidence to suggest the assertion is still a good one, even if the champions did leave Manchester with their manager, Carlo Ancelotti, questioning their attitude on the back of a third consecutive defeat against the team who have surged above them as football's richest club.

The game was perplexing for Ancelotti because it had exposed the kind of flaws to which the English game was starting to think Chelsea might be immune. The champions were not supposed to be a side who could be outmuscled in midfield, or who would lack the wit or gumption to do anything about it once it became clear that the occasion was in danger of becoming an ordeal.

"It was strange that we lost the fight in midfield," Ancelotti said. "Why? I don't know why, but that's the reason we lost the game. We didn't have the possibility to play our football. They had fantastic defence, fantastic power in their tackles. We lost a lost of balls, we didn't play quickly enough in the opponent's half, we weren't creative, we played too much as individuals, not as a team."

Hence his decision to substitute Didier Drogba, hitherto the most devastating forward in the league. Drogba's look as he left the pitch was a mixture of bemusement and scarcely disguised disdain. Chelsea will like to believe that, in football parlance, this was merely a blip – the exception to the rule when some of their football so far this season could have been set to music. A sense has developed that many Premier League opponents have come to fear them, in the same way that José Mourinho, newly installed at Real Madrid, complained last week of how Barcelona were regarded within La Liga.

Mourinho spoke of a culture whereby Barcelona's opponents "give away the game because they think they cannot win". The same, loosely speaking, has occurred in England. City, however, demonstrated all the attributes that are needed to bring Chelsea to their knees. They were fast to the ball and hard in the tackle. Mancini talked later of not giving Chelsea's attackers space and his players, in particular Gareth Barry and Nigel de Jong, carried out such instructions with an efficiency that suggested they have all grown to understand the Italian's philosophy.

"He has come from a country where defence is number one and he has brought that mentality with him," De Jong said. "It took time but the main focus for him is to get the defence right because he knows we have enough quality to score goals. That's what he preaches.

"His message is always the same: make sure we don't concede. He puts in so much time on the training pitch with the defenders to get them to realise that a clean sheet is holy."

To use De Jong's words, Mancini's men demonstrated that "Chelsea are not robots", winning thanks to Carlos Tevez's scurrying run just before the hour, a run that was finished off with a right-foot shot that went in off the post.

A snapshot of Chelsea's day came earlier in the match when Ramires, their newly recruited Brazilian, was taken down in a hard but legitimate challenge and, indignant that no free-kick had been awarded, made no attempt to rejoin play.

In that droll way of his, Ancelotti wondered about where the referee, Andre Marriner, had put his whistle.

"One player against another player is not dangerous but there were times when one of my players [Branislav Ivanovic] suffered three fouls at the same time. When that happens he has to whistle. But, of course, he couldn't whistle because he had left his whistle at home."

His words were accompanied by a rueful smile and he left it there, which is just as well because blaming the referee would have felt like a terrible cop-out. The truth was that Chelsea, famed for their competitive strengths and togetherness on the pitch, were beaten fair and square at their own game.

This is not a news report and may contain views expressed by the author which are not supported by GNM.