Barcelona comfortably saw off Real Madrid during their latest El Clásico meeting in Arlington.
The Spanish champions head into pre-season without Gavi and Iñigo Martínez ruled out through injury after initially being named as substitutes.
New signing Oriol Romeu sent his first warning shot with a long-range effort in the fourth minute that beat Thibaut Courtois but hit the crossbar.
Ousmane Dembélé soon put Xavi in the lead with a quick strike from a tight angle inside the area after Pedri immediately pulled him off the free-kick.
Their arch-rivals wasted a chance to equalize from the penalty spot after Ronaldo Araújo’s handball, only for Vinícius Júnior to shine with an effort against the woodwork.
Frenkie de Jong’s rash challenge on Éder Militão late in the first half prompted both sets of players to scuffle before the midfielder received a booking.
Aurélien Tchouaméni enjoyed Los Blancos‘ best chance of the opening 45 minutes with a well-struck free-kick that forced a stop from Marc-André ter Stegen.
The France international continued to threaten after the break with a powerful effort from distance that rattled the crossbar before Ter Stegen produced an impressive follow-up save.
But substitute Fermín López secured Barca’s opening win of the summer in emphatic style with a wonder-striker after just five minutes at the AT&T Stadium.
A third followed in the first minute of added time when Ferran Torres flicked the ball past the onrushing Courtois before acrobatically kicking into an empty net.