Roberto Mancini's men really struggled to get going as Swansea appeared fit and ready to match the reigning champions toe-to-toe in every area of the pitch.
What lessons can we take from this game, and why will it stay in our memories for years to come?
Manchester City were expected to exorcise their demons from a loss in Amsterdam on Saturday, but the fire was never truly lit underneath them as they limped to a 1-0 victory.
Michael Laudrup spoke before the game of fearing of a backlash from Roberto Mancini's men, but I've not seen this City side start so slowly in years.
If that's how they play after a tough European outing, they could have a few more difficult fixtures on the calendar between now and Christmas.
Since Brendan Rodgers' departure, Swansea City's game has changed.
They still take care of the ball in an efficient manner, but typically look to get the ball into the opposition's half much quicker than before.
That was not the case here though, and while some hesitation is understandable considering the stadium they were in, it seemed they were perfectly suited to play a slower pace.
Great versatility and flexibility was shown by the Swans.
Pablo Hernandez broke Swansea's transfer record this summer by signing for £5.5 million.
As such, a fair amount of expectation was placed on his shoulders and he's been decent so far.
The game at the Etihad stadium was his best showing in a Swans shirt to date, and his link-up play with Angel Rangel continues to improve and impress.
Swansea fans will hope he continues to grow and adapt.
This game will be remembered for all the wrong reasons.
The stretcher came on three times, and two players had to use it to leave the field. Michu recovered, but Michel Vorm and Micah Richards weren't so lucky.
Manchester City now have Richards, Pablo Zabaleta and Maicon injured. Who'd have thought having all those right-backs still wasn't enough?
James Milner, capable of filling in, is serving a suspension for his straight red card against West Bromwich. Where does Roberto Mancini turn now?
The commentators' unnecessary hype was way over the top, but this game will undoubtedly enter the record books for a surprising reason.
This was longest English Premier League game ever to have taken place, courtesy of three lengthy injury stoppages and 12 added minutes in the second half.
After a drab first 10 minutes, no one in their right mind would have guessed this game would be memorable, but spectators can justly state they witnessed history on Saturday.
Super sub Edin Dzeko has saved Roberto Mancini's bacon on numerous occasions already this season, most notably against West Brom and Fulham.
But he wasn't needed here as the Italian manager's faith in a lean, mean Carlos Tevez was rightly rewarded with the winning goal.
The Argentine had gone over a month without a goal, so it seems the striker has given his gaffer even more selection dilemmas ahead of next weekend's game.