Chelsea suffered a significant 3-1 defeat to Brighton & Hove Albion at Stamford Bridge, a match characterized by self-inflicted errors and a dramatic shift in momentum. Despite starting four former Brighton players, the Blues initially took control and opened the scoring through Enzo Fernandez. The Argentine midfielder, playing a more advanced role, netted his third goal of the season with a close-range header after a deflected Reece James cross, which followed an incisive diagonal pass from Moises Caicedo against his former club. This early lead gave Chelsea a deserved advantage, dominating possession with 70% and outshooting Brighton 9-0 in a comfortable first half.

However, the game irrevocably turned early in the second half. Trevoh Chalobah, who had been performing well despite a recent rough patch, was shown a red card in the 53rd minute. This came after a clumsy challenge on Diego Gomez, who was through on goal following an inexperienced and errant pass from Andrey Santos. Chalobah's dismissal, for denying a clear goalscoring opportunity, marked the second consecutive Premier League game Chelsea played with ten men, mirroring Robert Sanchez's red card a week prior against Manchester United.

Chelsea head coach Enzo Maresca expressed his frustration post-match, stating that his team could not continue to "give away presents" in terms of red cards, which he described as "big mistakes" that completely changed the game. He highlighted that despite being in control and dominating the first half, the plan disintegrated after Chalobah's sending off. The tactical adjustment saw young defenders Josh Acheampong and Jorrel Hato, both lacking extensive Premier League experience, thrust into a high-pressure situation.

Brighton capitalized on the numerical advantage with clinical efficiency. Danny Welbeck, 34, leveled the score in the 77th minute with a powerful header from Yankuba Minteh's cross, finding space where Chalobah would typically have been. The visitors then sealed their victory in stoppage time; Maxim De Cuyper headed in Brighton's second goal two minutes into added time, and Welbeck completed his brace, scoring his second and Brighton's third ten minutes into extra time after a quick transition. The home crowd's boos reflected the team's unraveling, with visiting fans taunting Chelsea by referencing their former Brighton players.

Individual performances for Chelsea varied significantly. Reece James was lauded for a strong display, both offensively with his assist for Fernandez and defensively, dominating Karou Mitoma. In contrast, Robert Sanchez was rated poorly for a shaky pass in the first half, though he couldn't do much about Brighton's goals. Andrey Santos's errant pass was directly implicated in Chalobah's red card, while substitutes like Malo Gusto struggled, being beaten too easily for Brighton's equalizing goal. Estevao showed early promise but faded, and Joao Pedro appeared tired and lacked an end product.

The defeat extends Chelsea's poor run to just one win in their last four games, highlighting growing concerns about discipline and an inability to adapt under pressure. Maresca now faces the challenge of preparing his squad amidst a lengthy injury list and a ban for Chalobah for the upcoming Liverpool match, with a Champions League encounter against former manager Jose Mourinho also on the horizon. The match also saw a mass shoving match between players as tensions flared, further illustrating the frustration within the Chelsea camp on a miserable day at Stamford Bridge, where even pre-match dry ice and blue smokebombs couldn't mask the team's ongoing struggles.