Chelsea manager Graham Potter returned to his old stomping ground as the Blues faced Brighton, less than two months after trading the Amex Stadium for Stamford Bridge, and two own goals ensured he suffered a first defeat in his new job.
The Blues almost got off to a nightmare start, relying on Thiago Silva to head off the line twice inside the opening five minutes to deny Leandro Trossard and Pervis Estupinan. The fast-starting Seagulls weren't to be denied, though, with tidy footwork from Trossard allowing the Belgian to round Kepa and find the bottom corner.
It was 2-0 inside 15 minutes, with Ruben Loftus-Cheek deflecting a corner into his own net, but Chelsea had their chances with Christian Pulisic missing a golden opportunity to pull one back. It was three before the break, though, with the unfortunate Trevoh Chalobah following Loftus-Cheek in scoring an own goal.
Potter made some tactical tweaks at the break, and was rewarded with a goal back from Kai Havertz, and then threw Ben Chilwell and Pierre-Emerick Aubameyang into the fold as the visitors looked to add to their tally. They continued to create, with Havertz blazing a great chance over the bar, but Brighton got a fourth through Pascal Gross late on to secure a first win under new boss Roberto De Zerbi.
The result saw Chelsea lose ground on their competitors in the Champions League chase, while bringing Brighton back within three points of their former manager's team. Here, Mirror Football looks at some of the main talking points from the game.
Boos for Cucurella
Seconds into the game, Chelsea defender Marc Cucurella was greeted by loud boos upon receiving the ball. The Spaniard was one of Brighton's star men last season, but the manner of his departure for Chelsea appeared to still be a sore point.
What did you make of Chelsea's performance? Have your say in the comments section
While Potter's achievements at the Amex Stadium may have earned him some goodwill, it was clear how some felt about Cucurella's decision to leave after just one year. The former Getafe man has had a difficult time of it lately, with Potter sacrificing him early on in Chelsea's draw with Man Utd, and the reception on the south coast is unlikely to have helped.
One man who did appear spurred on was Cucurella's replacement. Pervis Estupinan has had some impressive moments since joining from Villarreal, and was an attacking threat from the get-go as Brighton started like a train, and the Ecuadorian had a big part to play in the third Brighton goal.
Chelsea their own worst enemies
There were a couple of nervy moments early on, with Brazil defender Silva recovering well after some shaky defending to deliver a goal-line clearance. Little did we know that this would only be the start of the visitors' woes at the back.
The first own goal was the kind which a luckier player might have got away with, with Loftus-Cheek's instinctive movement deflecting the ball just under the crossbar instead of just over it. Similarly, Chalobah had to get something on Estupinan's low cross - it's just that he got enough to take it goalward but not enough to send it into the arms of Kepa.
The last time Chelsea went 3-0 down in the league, against Leeds in August, it came from a similar level of self-destruction. It's something they'll need to iron out, and that will be difficult with the likes of Reece James and N'Golo Kante unavailable.
Trossard loves a big game
Until Loftus-Cheek sent the ball into his own net, Leandro Trossard was the only player to score for brighton under Roberto De Zerbi. The former Genk star scored a hat-trick at Liverpool in the Italian's first game in charge, and was also on target in the 3-1 defeat at Manchester City.
The 27-year-old's record against the big teams is an impressive one. He also scored away at Liverpool, Arsenal and Tottenham last season, helping the Seagulls earn seven points from the three fixtures, and also netted as Brighton beat Man City in May 2021.
De Zerbi will still be keen to spread the goals around, of course, as he looks to make his mark on the south coast. For now, though, this kind of reliability in the bigger games can't hurt.
Battle of the Spanish keepers
Much has been made of Kepa's resurgence at Chelsea, and a potential Spain recall for the World Cup, but he'll have to get past Robert Sanchez to make it to Qatar. The Brighton keeper spent the first half playing like he knew just this, twice smartly denying Blues midfielder Conor Gallagher.
Kepa didn't seem hugely at fault for any of the three first-half goals, but did not emerge for the second period. The former Athletic Bilbao man was seen stretching towards the end of the first half, and fans will be waiting to learn whether he is indeed injured.
Unai Simon remains Spain's first choice, having started both Nations League games in September with Sanchez and David Raya on the bench. While the Brighton keeper had a couple of nervy moments coming off his line,
Potter reaction needed
Having lost none of his first nine games as Chelsea manager, Graham Potter will have been shocked by the half-time scoreline. The instant response from Havertz was testament to the manager's in-game tweaks, but now it's about how he responds to the full-time result.
The good news for the 47-year-old is that he has something of a free hit next time out. Chelsea's midweek win in Salzburg ensured they will progress to the last 16 of the Champions League as group winners, so there's a chance for a relatively pressure-free game at home to Dinamo Zagreb on Wednesday.
Keeping an unbeaten run going is a skill in its own right, but there's a different challenge in responding when that run comes to an end. Over to you, Graham.
