Morgan Rogers volleyed Chelsea in front after 77 seconds, the first goal Arsenal have conceded this season. Kai Havertz equalised in the 25th minute. Captain Martin Ødegaard scored the winner in the 50th minute.
Rogers, who joined Chelsea after Arsenal had chased him in the summer, finished from the edge of the box after a cleared free-kick. Arsenal’s response was immediate and loud. Havertz drove infield and shot between Maxence Lacroix’s legs to beat former Gunner Emiliano Martínez at the near post.
The winner was worked down the left. Christos Tzolis slipped the ball into the area; Havertz dummied; Ødegaard lashed high into the net. Chelsea were not finished. Pedro Neto hit a post before half-time and substitute Estêvão was denied late by David Raya.
Arsenal have nine points from three matches and have not lost to Chelsea in their last 11 meetings. Chelsea have six points from three and remain a threat, but they could not protect an early lead against the champions.
Mikel Arteta’s side had already beaten Aston Villa and entered this London derby as title favourites. Sunday tested that status. They passed it, not without alarm. Rogers’ goal was a warning; Havertz and Ødegaard were the answer. The table still reads Arsenal and City, maximum points, September barely begun.