Chelsea boss Carlo Ancelotti believes Manchester City will challenge his side for the Barclays Premier League title after the Blues' 100% start to the season was ended at Eastlands.
Carlos Tevez's excellent second-half winner proved the difference between the teams and lifted City to within four points of their opponents, who remain top of the table.
"They are fantastic players, a very good squad. They can fight for the title," he told Match of the Day.
City boss Roberto Mancini claimed on Friday Chelsea would retain their title "easily" and continued to tip them for glory in May after yesterday's game, but Ancelotti expects a genuine challenge to come from his fellow Italian's team.
Next up for Chelsea is a Champions League clash at home to Marseille before they take on Arsenal at Stamford Bridge and then travel to play Aston Villa at Villa Park, where they lost 2-1 last term.
But Ancelotti did not seem too concerned to be heading into those games on the back of a first defeat of the season.
"We lost also last year here, it's not a good pitch for us," he said.
"But we stayed at the top of the table, every game is a big test for us.
"Strange performance, but it can happen you are not able to score, this is football.
"You have to play against a strong team with a good performance. If you don't play at your best it's normal you don't score a goal."
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