All looked rosy in East Manchester when City took a 3-0 lead inside 53 minutes against the Dutch side, and they were cruising to success, still leading by three with a quarter of an hour to play.
Anis Hadj Moussa pulled one back after Josko Gvardiol's cheap giveaway in the defensive third, but the hosts then capitulated, conceding shortly after to Santiago Gimenez.
With one goal in it, Ederson then came flying out of his goal in an attempt to stop Igor Paixao from racing through, but missed the ball and the player, allowing the Brazilian to pick out David Hancko, who equalised against all odds.
Man City rack up the unwanted record in Feyenoord collapse
The most damning record City have set tonight is that this is now the latest a team has ever thrown a three-goal lead away in Champions League history.
No team had ever led 3-0 with less than 20 minutes remaining and failed to win in the UCL, but by leading by that scoreline on 75 minutes, City have obliterated that unwanted feat.
City have also joined a pair of English clubs who have thrown away a three-goal lead in the Champions League.
Arsenal did so against Anderlecht in 2014, and Liverpool did the same against Sevilla in 2017, but the Reds did go on to reach the final that season, so this result proves not all is lost just yet.
City's well-documented five-game losing run has now ended, but this will feel like just as much of a loss as all those that preceded it, and the 3-3 scoreline means City have conceded two or more goals in six straight games for the first time since 1963.
You also have to go back to 1989 for the last time Man City squandered a three-goal lead in any fixture, and it came against Harry Redknapp's Bournemouth side in a second-tier league encounter.
Only one of the current City squad was alive when that happened, and it was third-choice goalkeeper Scott Carson, who was just three years old at the time.
Guardiola sets another unwanted personal record
After losing five straight games for the first time in his managerial career following the 4-0 loss to Tottenham Hotspur at the weekend, manager Guardiola has set another unwanted first tonight.
In what was his 942nd match in management, Guardiola has seen his team go three goals up and fail to win for the first time, further illustrating quite how astonishing this turn of events was.
With Liverpool to come at the weekend, ensuring their winless run does not stretch to seven matches looks a very difficult ask too, and with confidence on the floor, and Guardiola stating his team are "fragile" at present, it seems a very likely possibility.
The absence of Rodri will once again be noted, and their record without the Spanish midfielder continues to get worse.
Since February 2023, City have lost just one of the 78 matches in which Rodri has played, winning over three-quarters of those games, but in the 28 matches where the 28-year-old has not been available, City's win percentage drops massively to 57%, and they have lost nine of those.