Since that day, when goals from Jeffrey Schlupp, Andros Townsend and Luka Milivojevic inflicted City's first home defeat of the 2018/19 Premier League campaign, Pep Guardiola's side have been beaten by four other sides from outside the big six.
Leicester and Newcastle stunned them with 2-1 home wins last season. In the new campaign, there have been defeats to newly-promoted Norwich, who won 3-2 at Carrow Road last month, and Wolves, who dealt another blow to their title prospects with their 2-0 win at the Etihad Stadium before the international break.
Manchester City have hit record-breaking heights in the Premier League under Guardiola, but what do those defeats tell us about their vulnerabilities? And how could Crystal Palace - a side with a penchant for upsetting the odds against the big guns - pull off another shock in Saturday's late kick-off at Selhurst Park?
Keep the shape and force them wide
City's technical prowess is such that they are always expected to dominate possession. But - as their defeats to Palace, Leicester, Newcastle, Norwich and Wolves have all shown - converting that dominance into results is not easy if their opponents get their gameplan right without the ball.
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Nuno Espirito Santo put the Wolves win down to his players "running like crazy", but there was a lot more to it than that. In fact, Premier League tracking data shows that Wolves covered a relatively modest 107.8km - only their third-highest total in a Premier League game this season and almost 10km fewer than Everton in City's previous game.
The win owed more to their disciplined and compact defensive shape. Instead of chasing down possession, Wolves sat back, soaked up the pressure and closed off the spaces in a 5-3-2 formation. As City's frustration grew, their focus dropped, with Wolves eventually punishing them on the break.
Adama Traore took the headlines for his goals, but his performance at right wing-back was also notable for its defensiveness. Like most of his team-mates, the Spaniard spent the majority of the game deep in his own half helping to keep City at bay. It is a reminder that there can be no passengers against such a formidable opponent.
When you play against City, what you have to think about is how you stop them from playing. This is the beginning of everything.
Another important factor in Wolves' win was the way in which they crowded out central areas, limiting the influence of David Silva, Ilkay Gundogan and, later, Bernardo Silva, and instead forcing City to the flanks in the knowledge that their centre-backs, led by the 6ft 1in Conor Coady, would have little trouble dominating City's diminutive forwards in the air.
This approach was also used by Palace, Leicester and Norwich and the statistics underline its effectiveness. Since the middle of December, including the 3-2 defeat to Palace, City have lost four of the five Premier League games in which they have made the most open-play crosses.
A deeper look at the numbers shows that, across those five games, only 21 of their crosses have even found a City player. In the defeat to Leicester, all 26 of their attempts were unsuccessful. And while they did score from one at Carrow Road, Sergio Aguero heading in from Bernardo Silva's centre, the numbers prove it is not an area of strength.
Strike in transition and pounce on errors
"You get your work-rate as it should be, you get your shape and discipline as it should be, then you also score goals," said Roy Hodgson.
The Crystal Palace boss made it sound simple after his side's win at the Etihad last year. But even if you are successful in blunting City's attacking threat, you must still find a way past them at the other end.
That task does at least appear easier now than it did previously. City have lost Aymeric Laporte and John Stones to injury, and having failed to replace Vincent Kompany during the summer, their current centre-back pairing consists of an error-prone Nicolas Otamendi and a repurposed Fernandinho, whose presence in midfield has been missed.
City's defence is there to be got at - only three sides have made more errors leading to shots this season, according to Opta - but their tendency to dominate possession, often high up the pitch, means that the best opportunities for their opponents are often found in transition, when the ball is turned over and Guardiola's men are caught out of position.
That's how Wolves succeeded at the Etihad Stadium two weeks ago, and Leicester's equaliser at the King Power Stadium back in December was another example. A move which began with Ben Chilwell tackling Danilo in the middle of the Leicester half ended with Marc Albrighton heading a Jamie Vardy cross past Ederson a few seconds later.
Leicester and Wolves were rewarded for their alertness to City's errors and so too were Norwich, whose third goal at Carrow Road last month, scored by Teemu Pukki, came after Emiliano Buendia had robbed possession from the dithering Otamendi on the edge of the City box.
Wilfried Zaha and Co. will be alive to those opportunities on Saturday, but they will also be aware that sometimes it comes down to moments of individual brilliance. Townsend's outstanding volley proved decisive the last time Palace beat City, while Leicester's winner a few days later came courtesy of similarly stunning effort by Ricardo Pereira.
There is no way of planning for those moments of inspiration. Instead, the challenge for City's opponents is to put themselves in a position from which they can make a difference.
Capitalise on set-piece chances
The Norwich game was a reminder of another area in which City are vulnerable. Guardiola's men have only conceded 32 goals in 46 Premier League games since the start of the last season, but their total includes 12 from corners and free-kicks.
It is the same number as strugglers Southampton, only one more than Bournemouth, and means they have conceded a higher percentage of their goals from dead balls than any other side in the division.
Daniel Farke's side were able to capitalise when Kenny McClean rose unmarked to head home Buendia's corner for the opener at Carrow Road, but the goal that emphasised the issue most strongly this season came in the 2-2 draw with Tottenham at the Etihad Stadium, when the 5ft 7ins Lucas Moura beat Kyle Walker and Laporte to head in Erik Lamela's delivery.
The set-piece frailty is another factor which could work in Palace's favour on Saturday. Roy Hodgson's side already know what it takes to upset the champions. But City's defeats since then give them more food for thought. Another Palace victory might not be such a shock this time around.
Watch Crystal Palace vs Manchester City live on Sky Sports Premier League HD from 5pm on Saturday; Kick-off 5.30pm