Arsenal had not conceded a goal in either of their first two league matches. Two minutes into the London derby they had, Morgan Rogers striking from outside the box after Jorrel Hato's headed pass from a set piece, and the Emirates had to find out what this team looks like from behind.
It looks like this: sixteen shots, nine on target, and a 2-1 win by the hour.
Two goals from distance and a fast break
Kai Havertz levelled on 25, left footed from outside the area after Declan Rice picked him out. Martin Ødegaard won it on 50, left footed from the centre of the box, finishing a break Christos Tzolis started.
Both were the kind of goal a side scores when the opposition sits in and dares them to try from range, and Chelsea did exactly that after taking the lead.
Emiliano Martínez made eight saves
That is the number that explains the scoreline. Chelsea's summer goalkeeper, signed from Aston Villa for under £10 million on the last weekend of the window, faced nine shots on target and stopped eight of them. David Raya made four at the other end.
Without Martínez this is four or five. With him it was one goal from a corner away from a point.
Chelsea's afternoon in bookings
Four yellow cards, sixteen fouls, and a defence that Frank Leboeuf called fragile on the broadcast. João Pedro was booked on 14, Cole Palmer on 45, Maxence Lacroix on 58, Rogers on 83. Palmer had three shots and two on target, and was the closest they came to a second.
They are now the club that spent more than anyone in Europe this summer, eleven signings for €408 million, sold Enzo Fernández to Manchester City for £125 million on deadline day, and has lost at the Emirates with no European football to fall back on.
Arteta's bench is a squad now
Piero Hincapié and Martín Zubimendi came on together on 67, Mikel Merino on 77, Viktor Gyökeres for Havertz on 78, Noni Madueke for Bukayo Saka on 90. That is five changes made to protect a one-goal lead, not to chase a game.
Saka had four shots and three on target before he went off, more than any Chelsea player managed.
Where it leaves them
Three wins from three, six scored, one conceded, and that one arrived two minutes into their third match. Arsenal have not dropped a point since the season began.
