Kai Havertz scored Arsenal's goal in front of a crowd of 69,879 at the home stadium of the NFL's Philadelphia Eagles.
Egyptian Salah opened the scoring for Liverpool in the 13th minute, outpacing the defenders to latch onto Harvey Elliott's defence-splitting pass. The striker shrugged off the attentions of Arsenal centre-back Gabriel and fired a low left-footed shot past Arsenal goalkeeper Karl Hein.
Carvalho doubled Liverpool's lead in the 34th minute, with Elliott again the provider. The 21-year-old Portuguese winger ran onto a perfectly lofted Elliott pass into the box and fired home a crisp right-foot volley through Hein's legs.
Arsenal's newly signed 22-year-old Italian defender Riccardo Calafiori was not in the Gunners' lineup.