Chelsea lost their first game under Graham Potter as the manager endured a nightmare return to Brighton, losing 4-1 at the Amex Stadium.

It was a first half worthy of Halloween weekend as a litany of errors saw the Blues deservedly 3-0 down at the break.

Brighton pressed Chelsea from the off and went ahead inside five minutes. Thiago Silva's poor pass - not the first he had made in the game either - ricocheted off Leandro Trossard from close range. It landed into Premier League debutant Kaoru Mitoma, who drove into the area and skipping over the Chelsea shirts before finding Trossard.

The Brighton forward then lifted the ball over the oncoming Kepa Arrizabalaga for his fifth goal under Roberto De Zerbi. It was also the first time the Seagulls have gone ahead against Chelsea in the Premier League.

Brighton's second came nine minutes later as Chelsea continued to be architects of their own downfall. In a flurry of corners, Solly March delivered a fine effort which a rooted Ruben Loftus-Cheek turned into his own net.

It was another own goal for Brighton's third too. Moises Caicedo expertly found Pervis Estupinan down the left of the area, with the latter's cross into the six-yard box turned home by Trevoh Chalobah's outstretched foot (42), leaving Potter dismayed in the away dugout.

Chelsea had the exact response needed early in the second half as they nabbed a goal back. It was a wonderful, sweeping cross from Conor Gallagher that was nodded home by Kai Havertz (48).

Despite Chelsea dominating the second half, it was Brighton who added a late fourth as Pascal Gross bought up 50 goal involvements for the club. Julio Enciso forced two saves from second-half substitute Edouard Mendy, but Gross was there to send the ball home (90+2) and round off a fine afternoon for the Seagulls.

The result marked the first time Brighton have beaten Chelsea in league football, as well as De Zerbi's first win as Seagulls manager. It sends Brighton into seventh with 18 points.

Chants of 'you're getting sacked in the morning' were aimed at Potter from his former fans and he was booed both before and after the game. However, Chelsea stay in fifth ahead of the remaining games this weekend.

How Brighton beat Chelsea for the first time

The tone of the game was set inside three minutes. A poor pass out from Silva saw Caciedo nod the ball into the path of Trossard at the top of the area. Kepa Arrizabalaga was well off his line as the Brighton forward swept the ball towards an open net, but Silva scrambled back to clear it away.

It was Silva's error again that led to the Brighton opener, before a quick second thanks to Loftus-Cheek's own-goal. Chelsea were already 2-0 down inside 14 minutes and needing a response, finally began to work Robert Sanchez in the Brighton goal.

Gallagher forced a save from the goalkeeper, with Christian Pulisic firing the rebound just wide. Gallagher again went close soon after, nodding a superb cross from Raheem Sterling goalwards, but Sanchez pushed it away once again.

But it was Brighton who continued to look the brightest and went close again on the half hour. After some lovely play between Trossard and March in a packed area, Caciedo skimmed the post and the side of the net with his own effort. However, just a minute before half-time, Chalobah poked the ball past his own goalkeeper to add a Brighton third.

Chelsea were improved after the break, and pulled a goal back early on. Brighton continued to live dangerously, with Sanchez needed to keep out Mount's attempted cross through the area.

Both sides continued to see chances with the intensity and pace of the game remaining high. A poor pass from Mendy went straight to the feet of Mitoma, who picked out Trossard again. He tried to chip the goalkeeper, but Mendy was up high to stop it. At the other end, Pierre-Emerick Aubameyang tried his luck from range, but Sanchez pushed it away.

Brighton wrapped up the points in the second minute of added time thanks to Gross' finish, capping off Potter's miserable return to the south coast.

Man of the match - Leandro Trossard

A player who is in-form and full of confidence, Trossard added another goal to his tally on Saturday. He had the most shots in the game (6), with four on target and the joint-highest number of touches in the opposition area (10 - level with Havertz).

Player ratings

Brighton: Sanchez (7), Webster (7), Estupinan (8), Dunk (7), March (8), Mac Allister (6), Caicedo (7), Trossard (8), Mitoma (8), Gross (7), Lallana (6).

Subs used: Enciso (7), Lamptey (6), Sarmiento (n/a).

Chelsea: Kepa (6), Chalobah (6), Silva (5), Cucurella (6), Sterling (6), Loftus-Cheek (6), Kovacic (6), Gallagher (6), Mount (6), Pulisic (6), Havertz (6).

Subs used: Mendy (6), Aubameyang (6), Chilwell (6), Broja (n/a), Ziyech (n/a).

Man of the match: Leandro Trossard.

England World Cup watch

Raheem Sterling, Conor Gallagher, Mason Mount and Ruben Loftus-Cheek all started for Chelsea. Of course, Loftus-Cheek will have the spotlight on him after his own goal.

There were a few decent crosses from Sterling and Mount tested Sanchez in the second half, but neither had a large effect on the game. Gallagher picked up an assist for the afternoon, with his lofted cross nodded home by Havertz.

Gallagher and Sterling were both substituted, while Mount and Loftus-Cheek played the whole 90 minutes. Ben Chilwell came on in the 64th minute and largely acquitted himself well.

Opta stats - Chelsea's double own goals

- Brighton secured their first league victory over Chelsea at the 15th attempt of trying (D4 L10). Indeed, this was the first time the Seagulls have scored more than one goal in a league match against the Blues.

- Chelsea conceded double the number of goals today (4) as they did in their first five league matches under the Englishman (2).

- Chelsea scored two own goals in a single Premier League game for the first time, becoming the first side to put through their own net twice in the opening 45 minutes since Everton against Southampton in April 2014.

What's next?

Chelsea complete their Champions League group stage campaign at home to Dinamo Zagreb on Wednesday, before facing three teams in the top four before the World Cup break.

The Blues host Arsenal on November 6 before going to Manchester City for the third round of the Carabao Cup three days later, live on Sky Sports with kick-off at 8pm. Graham Potter's side then travel to Newcastle for Saturday Night Football on November 12, kick-off at 5.30pm.

Brighton go to Wolves next Saturday, before travelling to Arsenal for the third round of the Carabao Cup four days later. The Seagulls' last match before the World Cup is against Aston Villa on November 13.

Teams

Brighton & Hove Albion Sanchez; Dunk (c), Webster, Estupinan, March, Mac Allister, Caicedo, Trossard (Sarmiento 87), Gross, Mitoma (Lamptey 73), Lallana (Enciso 65)
Subs Not Used Steele, Turns, Furlong, Moran, Gilmour, Undav
Booked Enciso
Goals Trossard 5, Loftus-Cheek 14 (og), Chalobah 42 (og), Gross90+2

Chelsea Kepa (Mendy 46), Chalobah, Silva (c), Cucurella (Chilwell 64), Pulisic (Broja 79), Kovacic, Loftus-Cheek, Sterling (Aubameyang 63), Mount, Gallagher (Ziyech 79), Havertz
Subs Not Used Azpilicueta, Jorginho, Zakaria, Hutchinson
Booked Kovacic, Sterling
Goals Havertz 48

Attendance 31,746

Referee Andy Madley

VAR Lee Mason