Lionel Messi scored in a joint record 16th Champions League season and 17-year-old Pedri netted his first senior goal as Barcelona beat Ferencvaros.
Messi struck from the penalty spot to give Barca the lead after he was felled at the end of a weaving run.
Ansu Fati volleyed Barca’s second, with Philippe Coutinho adding a third.
Gerard Pique was sent off for a foul that set up Ihor Kharatin to narrow the deficit with a penalty, but Pedri and Ousmane Dembele ensured Barca’s win.
Pique’s dismissal is a costly one for the Spanish side, with the experienced defender now suspended for their trip to Italian champions Juventus in gameweek two.