Manchester City produced a remarkable defensive performance to beat Manchester United 1-0 at Old Trafford, despite playing with 10 men for more than an hour.
Phil Foden was sent off in the 23rd minute after reacting to a kick from Bruno Fernandes, leaving City with a numerical disadvantage for the majority of the 199th Manchester derby.
But instead of collapsing, Enzo Maresca's side stayed organised and eventually found the breakthrough through Erling Haaland.
The Norwegian striker struck in the 60th minute, turning home a Joško Gvardiol cross to score his ninth Manchester derby goal in just 11 appearances against United.
The goal was initially ruled out for offside before VAR intervened. Haaland was eventually deemed onside, while Enzo Fernández's position was judged not to constitute interference with play.
That decision became one of the major talking points of the match, with United furious that the goal was allowed to stand.
ProRef subsequently admitted that the officials made an error of judgement and should have recommended an on field review.
United had opportunities to punish City after Foden's dismissal. Marcus Rashford and Kobbie Mainoo both hit the woodwork, but Michael Carrick's side struggled to make their one man advantage count.
City's defence, led by Marc Guéhi and Rúben Dias, remained disciplined throughout, while Gianluigi Donnarumma produced a crucial late save to deny Bryan Mbeumo and protect the lead.
The victory means City have won all four of their Premier League matches this season, giving them 12 points from 12 available.
They remain level on points with Arsenal at the top of the table.
For United, the defeat leaves them with just four points from their opening four league games, a disappointing start to Michael Carrick's campaign.
Haaland's decisive finish also moved him level with Sergio Agüero on nine goals in Manchester derbies, putting him among the most prolific scorers in the fixture's history.
Man of the Match... Marc Guéhi was named City's standout performer in the club's official match report for his commanding defensive display.