Arsenal and Chelsea went into the derby with a full haul after two rounds. The rivals produced an eventful first half - but after the break the home team took command.
Sweden's national team star Viktor Gyökeres, who had not been in the starting line-up at the start of the season, once again had to settle for a place on the substitutes' bench when the starting eleven was announced.
Chelsea didn't need long to take the lead. It was 1-0 after just 77 seconds, when billion-pound signing Morgan Rogers found the right spot and scored the first goal of the match after a tangled set-piece situation.
Disallowed goal
Arsenal then thought they had equalised. Riccardo Calafiori held his own in a chaotic situation and managed to get the ball past Emiliano Martinez. The joy was short-lived, however. A VAR review showed that Ezri Konsa was in an offside position earlier in the attack, and the goal was disallowed.
The equaliser was to come, however. Kai Havertz stepped up and made it 1-1 with a long-range shot that outwitted the Chelsea goalkeeper.
The teams thus went into the break tied at 1-1.
Arsenal then got off to a dream start in the second half when Martin Ødegaard struck and completed the turnaround by putting the home team 2-1 ahead, a result that stood for the rest of the game.
Gyökeres with late entry
Viktor Gyökeres was substituted with just over ten minutes left in the match but never had time to make his mark on the game.
Earlier on Sunday, Manchester United were on the verge of three strong points away to Everton. But with the last kick of the match, former Arsenal defender Ainsley Maitland-Niles equalised with a long-range shot that hit the crossbar, making it 2-2.
Manchester City top the Premier League table after three rounds with a maximum of nine points. Arsenal have the same points tally but have scored fewer goals.
