Second-half goals from Reece James and Kurt Zouma gave Chelsea a winning start to their season.
Jorginho put them ahead from the penalty spot and James brilliantly blasted home just after Leonardo Trossard had hauled Brighton level early in the second half.
Zouma’s deflected shot sealed the victory for Frank Lampard’s side.
Jorginho coolly netted after Timo Werner – who made his debut along with Kai Havertz – was brought down by keeper Mat Ryan midway through the first half.
Brighton troubled Chelsea and deservedly equalised when Trossard fired into the far corner from near the right-hand edge of the penalty area.
But James’ cracking strike – his first Premier League goal – restored Chelsea’s lead a couple of minutes later.
And Zouma’s shot from James’ corner was inadvertently diverted past Ryan by Seagulls defender Adam Webster.
Chelsea: Kepa, James, Christensen, Zouma, Alonso Jorginho (Azpilicueta 85), Kante, Loftus-Cheek (Barkley 61), Mount, Havertz (Hudson-Odoi 81), Werner.
Subs not used: Caballero, Rudiger, Abraham, Giroud.