Brighton beat Arsenal 3-0 at the American Express Stadium on Saturday, ending the champions' unbeaten start to the Premier League season and giving Arsenal their first league defeat since April.

The margin is the story. Arsenal had conceded one goal in the league all season and arrived on a seven-match winning run in all competitions, Press Association reported. Both runs ended inside 90 minutes.

Pascal Gross scored on 31 minutes and Charalampos Kostoulas made it 2-0 on 45. Chema Andres added the third early in the second half.

Brighton's finishing did the damage, not their territory

Opta Analyst put Brighton's expected goals at 1.33 and Arsenal's at 1.58, so the visitors created the better raw chances and lost by three. Brighton had 17 shots to Arsenal's 11, and Opta counted nine turnovers won by Brighton in the final third, the most any side has managed against Arsenal since December 2023.

That is the pattern of Brighton's season so far. They have scored 16 goals in five matches, which Opta records as the most by any side since Manchester City's 19 in 2022/23, and Gross leads the division with six goal involvements from three goals and three assists. beIN Sports had Brighton up to third by the end of the afternoon.

Opta also logged this as Arsenal's heaviest league defeat as reigning champions since October 1989, and their biggest Premier League loss since May 2023, when Brighton won by the same score. It is the third season running that Brighton have beaten the reigning champions at home.

Arteta treated the result as a lesson rather than an accident

"I am extremely disappointed. Brighton deserved it, they were the better team," the Arsenal manager said afterwards.

It's a big lesson for us all to understand what it takes to win at this level.

Mikel Arteta, after Brighton 3-0 Arsenal

Fabian Hürzeler kept his own reaction narrow. "It is very important to stay humble. We have to enjoy this moment but understand why we had success," the Brighton head coach said.

Arsenal had gone top of the table after their win at Sunderland. That perfect record is gone, and Arteta is left rebuilding a defensive record rather than protecting one.

Arsenal are back on 10 October

The international break follows, and Arsenal's next league game is at home to Leeds United on Saturday 10 October. That gives Arteta a fortnight with the players who stay behind, and a defence to reset: before Saturday his side had conceded once in the league all season, and they have now shipped three in an afternoon.

Brighton, meanwhile, go into the break having beaten the reigning champions at home for the third season in a row, with Gross and Kostoulas both scoring and Opta's numbers pointing at what Hürzeler's side did with the ball once they won it back.