Robert Lewandowski scored his fifth goal in three LaLiga games and Raphinha opened his Barcelona account in a 3-0 victory over fragile Sevilla.
Raphinha opened the scoring with a simple header and Lewandowski capitalised on Sevilla's defensive frailties to double Barca's lead in the first half.
Eric Garcia got in on the act with his first senior goal in the second half and Jules Kounde provided two assists against his former club on his return to the Ramon Sanchez-Pizjuan, where Barca cruised to a third consecutive victory.
Angry Sevilla fans turned voiced their disapproval during a defeat that leaves them with just one point from four matches.
Sevilla made a promising start and Marc-Andre ter Stegen produced an excellent one-handed save to deny Ivan Rakitic when the former Barca midfielder went one-on-one with the goalkeeper after some slack defending.
The Blaugrana sparked into life and produced a devastating counter-attack to take the lead after 21 minutes, with Fernando clearing off the line after Lewandowski dinked the ball over Yassine Bounou but only onto the head of Raphinha, who could not miss from point-blank range.
Lewandowski made Los Rojiblancos pay for leaving him unmarked nine minutes before the break, taking a pinpoint pass from Kounde on his chest and volleying inside the bottom-left corner with his right foot.
Kounde somehow failed to add a third against his former club when he headed wide unchallenged from only five yards out with Sevilla all at sea at the back.
Defender Kounde turned provider for a second time early in the second half, heading Raphinha's delivery from the right across goal unmarked to give Garcia a tap-in.
Bounou showed sharp reflexes to keep out another Lewandowski volley after Sergi Roberto picked the striker out with a whipped cross from the right.
Lewandowski failed to chip Bounou when he was sent clear again as the busy keeper stood tall and stuck out a palm and Frenkie de Jong was unable to finish following up on a painful evening for Julen Lopetegui's struggling side.