Phil Foden lasted 23 minutes. Erling Haaland made the other 67 count.
City beat Manchester United 1-0 in the Premier League on Sunday, a result that keeps them on 12 points from a possible 12, level with champions Arsenal at the top. It was a win built on stubbornness as much as quality, the kind of afternoon that tests a squad's nerve rather than its flair.
Foden's dismissal came early. A boot up into Bruno Fernandes, spotted by referee Michael Oliver, who produced a straight red. It was a needless piece of contact and it left City a man down for more than an hour.
What followed was the sort of rearguard that rarely makes the highlight reels but decides titles. United pushed, City absorbed, and the game turned on one moment just before the hour.
Haaland's 60th-minute strike proved the difference between the rivals. It was not straightforward. The striker appeared to be in an offside position in the buildup, and the goal was initially ruled out. A careful VAR check followed, the decision was overturned, and the goal stood.
That goal took Haaland's tally against United to nine in total, including a third at Old Trafford. In doing so he became the highest scorer in the Manchester derby for Premier League games, moving past Sergio Aguero and Wayne Rooney, both of whom had struck eight times. Only West Ham (11), Wolves (10) and Crystal Palace (10) are now the teams he has scored more against in the Premier League.
United had their chance to snatch a point. In the 95th minute, Bryan Mbeumo had the goal in front of him but saw his effort denied by Gianluigi Donnarumma. It was the last meaningful act of an afternoon that City will file under 'job done' rather than 'vintage'.
Ten men, one moment of quality, three points. That is the sort of afternoon that keeps a title race ticking over without ever feeling comfortable.