Brighton made a blistering start and went ahead in the fifth minute through Leandro Trossard. Chelsea captain Thiago Silva twice cleared off his line in the opening stages, before Trossard collected a pass from Mitoma, rounded visiting goalkeeper Kepa Arrizabalaga and fired home.
Albion doubled their advantage in the 14th minute, with recalled Chelsea midfielder Loftus-Cheek diverting the ball into his own goal via the underside of the crossbar following a Solly March corner.
Chants of ‘Potter what’s the score?’ grew louder among home supporters and were swiftly followed by ‘You’re getting sacked in the morning’.
Brighton were 3-0 up in the 42nd minute after Chelsea defender Trevoh Chalobah diverted the ball into his own net following Estupinan’s pull back from the left.
Chelsea pulled a goal back within three minutes of the restart. Kai Havertz headed home unmarked following Conor Gallagher’s cross from the right.
But Albion deservedly had the last say as Pascal Gross sealed Brighton’s success by making it 4-1 in added time.
Here’s how the Albion players rated...
1. Rob Sanchez 8/10
Looks every inch a Spain international goalkeeper. Fine saves to deny Gallagher and Sterling in the first half. Distribution sound. Photo: GLYN KIRK
2. Adam Webster 8/10
Webster Sound alongside Dunk in the first half. Unlucky with a header from a corner that flashed past the post Photo: Bryn Lennon
3. Pervis Estupinan 8/10
Excellent down the left and linked well with Mitoma. Bombed forward with intent and calm on the final ball. Looked good and best game in an Albion shirt. Photo: GLYN KIRK
4. Lewis Dunk 10/10
Outstanding. This De Zerbi system looks perfect for him. He pinged a passes from the back, solid in the tackle and positional play outstanding. Staggering he remains out of the England conversation. Photo: Alex Pantling