Potter's Blues crushed by former club Brighton
Graham Potter suffered a crushing first defeat as Chelsea head coach on his return to former club Brighton and Hove Albion, which claimed a thrilling 4-1 win at Amex Stadium on Sunday (AEDT).
Potter was aiming to become the first English boss in Chelsea's history to go unbeaten in his first 10 games, but the Seagulls were ravenous as they earned new coach Roberto De Zerbi his maiden win.
Chelsea's defeat was essentially confirmed by half-time after Leandro Trossard's early strike was added to by own goals from Ruben Loftus-Cheek and Trevoh Chalobah.
Kai Havertz pulled one back just after half-time, but magic was in short supply for Potter and the Blues as Pascal Gross added gloss to the scoreline late on.
De Zerbi's side was straight on the front foot and scored in the fifth minute.
Kaoru Mitoma's incisive run was followed by an intricate pass into the box for Trossard, who showed exceptional composure to round Kepa Arrizabalaga and slam home.
It was 2-0 soon after, as Loftus-Cheek miscued a clearance from a corner and found his own net.
Moises Caicedo was denied by the post just after the half-hour mark, but Brighton still managed to extend their lead before the break, Chalobah poking Pervis Estupinan's pass beyond Kepa.
Potter withdrew Kepa for Edouard Mendy at the break and Chelsea quickly got itself a lifeline, Havertz nodding in Conor Gallagher's cross.
The goal was a precursor to prolonged Chelsea pressure, but no comeback followed and Brighton got a fourth in stoppage-time, Gross pouncing on the rebound after Julio Enciso tested Mendy's palms.
