Two days after it was confirmed they had acquired a Major League Soccer franchise, City did their push for recognition in the United States no harm with an entertaining display in St Louis.
City fell behind to Demba Ba, Cesar Azpilicueta and Oscar goals despite dominating the first half but Javi Garcia began the fightback, Edin Dzeko struck twice and Micah Richards grabbed a late winner.
The match at Busch Stadium, home of the baseball's St Louis Cardinals, was a 48,263 sell-out although, with the majority supporting Chelsea, there was perhaps an indication of how much work City still have to do in the country.
The match hardly had the intensity of the FA Cup semi-final between the two clubs last month but nor was it a half-hearted contest and both line-ups were strong.
Sergio Aguero had an early effort ruled out for offside and then put a rebound wide after Petr Cech had saved his point-blank effort.
Chelsea grabbed the lead against the run of play when England's Joe Hart had a moment to forget, missing a Juan Mata cross and allowing Ba to head home.
City responded with Yaya Toure forcing more good saves from Cech with a shot on the turn and a long-range strike.
Carlos Tevez sent an overhead kick narrowly over the bar before Chelsea benefited from a soft penalty decision on the stroke of half-time as Karim Rekik was adjudged to have bundled over Mata.
Azpilicueta put his spot-kick just beyond Hart's reach and Chelsea grabbed a third early in the second period after both teams made a raft of substitutions.
City gave the ball away in front of their own area and Oscar danced through to take the ball round replacement goalkeeper Richard Wright.
City hit back with two goals in quick succession just after the hour.
Garcia turned in from a corner moments after substitute goalkeeper Jamal Blackman came on and Dzeko then finished expertly from a well-weighted James Milner pass.
Milner almost equalised but Blackman stretched to get a foot to his close-range volley and then reacted quickly to keep out another Dzeko attempt.
The leveller came five minutes from time as Tevez slipped in Dzeko and Richards won it when he turned in a Garcia nod-down.
The sides do it all again at Yankee Stadium in New York on Saturday.