Arsenal suffered their first defeat of the season after Brighton stunned the champions 3-0 at the Amex Stadium.

The Seagulls entered the game in a confident mood following wins over Coventry City and Manchester United and quickly put Arsenal under pressure.

Pascal Gross opened the scoring for Brighton in the 31st minute, firing from the edge of the box with his effort going in off the post.

Arsenal, who had won their previous nine league games and seven matches in all competitions at the start of the campaign, struggled to cope with Brighton’s intensity and looked uncharacteristically nervous in possession.

The Gunners came close to an equaliser shortly before half-time when Bukayo Saka found himself with an opportunity in the area after Martin Odegaard’s effort was deflected, but he failed to convert.

Brighton immediately punished Arsenal’s missed chance as Charalampos Kostoulas doubled the lead seconds before the break, turning on the edge of the box before firing past David Raya.

Mikel Arteta made no changes at half-time as he looked for a response from his players, but Brighton extended their advantage 12 minutes into the second half.

Chema Andres headed home from a Gross corner to make it 3-0 and put the result beyond Arsenal’s reach.

The victory capped a remarkable week for Brighton, who had scored 11 goals across wins over Coventry, Manchester United and Arsenal, including a 3-2 comeback victory at Old Trafford in the Carabao Cup.

Pascal Struijk, making his first Premier League start for Brighton since joining from Leeds in the summer, nearly added a fourth from another corner but headed wide under pressure.

Arsenal had a late chance to reduce the deficit when Kai Havertz broke through on goal, but he shot straight at Brighton goalkeeper Bart Verbruggen.

Matt O’Riley was also denied by Raya at the other end as Brighton continued to threaten.

The defeat left Arsenal second in the table on goal difference, having played one game more than Manchester City, who host Sunderland on Sunday.

Brighton moved up to third, two points behind the leaders.

Arsenal suffered their first defeat of the season after Brighton stunned the champions 3-0 at the Amex Stadium.

The Seagulls entered the game in a confident mood following wins over Coventry City and Manchester United and quickly put Arsenal under pressure.

Pascal Gross opened the scoring for Brighton in the 31st minute, firing from the edge of the box with his effort going in off the post.

Arsenal, who had won their previous nine league games and seven matches in all competitions at the start of the campaign, struggled to cope with Brighton’s intensity and looked uncharacteristically nervous in possession.

The Gunners came close to an equaliser shortly before half-time when Bukayo Saka found himself with an opportunity in the area after Martin Odegaard’s effort was deflected, but he failed to convert.

Brighton immediately punished Arsenal’s missed chance as Charalampos Kostoulas doubled the lead seconds before the break, turning on the edge of the box before firing past David Raya.

Mikel Arteta made no changes at half-time as he looked for a response from his players, but Brighton extended their advantage 12 minutes into the second half.

Chema Andres headed home from a Gross corner to make it 3-0 and put the result beyond Arsenal’s reach.

The victory capped a remarkable week for Brighton, who had scored 11 goals across wins over Coventry, Manchester United and Arsenal, including a 3-2 comeback victory at Old Trafford in the Carabao Cup.

Pascal Struijk, making his first Premier League start for Brighton since joining from Leeds in the summer, nearly added a fourth from another corner but headed wide under pressure.

Arsenal had a late chance to reduce the deficit when Kai Havertz broke through on goal, but he shot straight at Brighton goalkeeper Bart Verbruggen.

Matt O’Riley was also denied by Raya at the other end as Brighton continued to threaten.

The defeat left Arsenal second in the table on goal difference, having played one game more than Manchester City, who host Sunderland on Sunday.

Brighton moved up to third, two points behind the leaders.