Lionel Messi scored a hat-trick to help see off Espanyol in the Catalan derby and take Barcelona top of La Liga.
Messi collected Ivan Rakitic's pass before curling in the opening goal and added a second from close range following Jordi Alba's pull-back.
The Argentina forward completed his 38th Barcelona hat-trick when he finished off from another Alba cross.
Gerard Pique headed in from a corner before Luis Suarez converted from debutant Ousmane Dembele's low pass.
Dembele, the world's second most expensive footballer who joined from Borussia Dortmund for a fee that could rise £135.5m, came on as a second-half substitute.
Barcelona are the only team with a 100% record and are yet to concede a goal, while La Liga champions Real Madrid are sixth after a 1-1 home draw against Levante earlier on Saturday.
Have your say
More Sports Headlines
- U-17 WWC: Two straight wins for Ghana after hard-fought Finland victory
- Former 'Black Queens' players lead 2018 TOTAL AWCON Trophy tour in Accra
- Asante Kotoko policy analyst counts benefits of Soccerex exhibition
- Kenya loses CAS appeal over Women's Nations Cup exclusion
- Nigeria still AWCON favourites, but face tougher task than normal
- Black Queens begin quest for first AWCON title on Saturday
- VAR set to be used in Premier League next season
- Kwesi Appiah defends Ghana's big-name recalls
- Mourinho better than Guardiola - Maradona
- Wayne Rooney to be England captain during farewell appearance
- 46 Sports Associations to benefit from GHASSEP Seminars
- UGBS Marketing lecturer argues Hearts-Umbro deal will cut local jobs
- U-17 WWC: All the best photos as Black Maidens make winning start
- Claudio Ranieri appointed as Fulham boss
- Santiago Solari appointed Real Madrid head coach until 2021