Alexis Sanchez's second-half winner helped leaders Barcelona beat neighbours Espanyol and stretch their unbeaten La Liga start to a 12th game.
Barcelona dominated possession and territory against their city rivals, but did not make a breakthrough until Sanchez tapped in Neymar's low cross.
Dani Alves hit the Espanyol post, soon after he almost gifted Victor Sanchez a first-half goal for the visitors.
Lionel Messi failed to score in his fourth successive La Liga match - his longest goalless run since April 2011
Barca are four points clear of Atletico Madrid, who host Bilbao on Sunday.
Under new boss Gerardo Martino, the Catalans have won 11 of their opening 12 matches, including
last weekend's 2-1 home win over arch-rivals Real Madrid.
But the Spanish title holders were not at their most fluent against an Espanyol side that started the game in eighth place.
Despite their control, Barca rarely forced Espanyol goalkeeper Kiko Casilla into a first-half save and were fortunate not to fall behind after 38 minutes.
Brazil right-back Alves failed to deal with a hopeful through ball and it allowed Espanyol midfielder Sanchez to poke goalwards. But the ex-Barcelona player saw his effort blocked by home goalkeeper Victor Valdes.
Alves almost made amends for his error in the final moments of the first half when his low shot, following a neat one-two with Sergio Busquets, struck the base of Casilla's right-hand post.
Barcelona have won 21 consecutive home league games - their best run since 1974.
And Barcelona's dominance continued after the break. Espanyol goalkeeper Casilla kept his side level by diving low to his right to push out Lionel Messi's header, but he was powerless to stop Chile forward Sanchez netting the opener.
Barca's £50m summer signing Neymar drilled a low cross through a body of Espanyol defenders and an unmarked Sanchez, who also scored against Real Madrid on Saturday, was waiting at the far post to tap in.
Second-placed Atletico have won 10 of their opening 11 games, while third-placed Real Madrid, who visit Rayo Vallecano on Saturday, are a further five points behind.
- 01 Valdés
- 22 Dani Alves
- 02 Montoya
- 16 Busquets
- 03 Piqué
- 14 Mascherano Booked (Bartra - 89' )
- 06 Xavi
- 08 Iniesta (Fábregas - 86' )
- 10 Messi
- 09 Sánchez (Pedro - 83' )
- 11 Neymar
- 04 Fábregas
- 07 Pedro
- 13 Pinto Colorado
- 15 Bartra
- 17 Song
- 20 Tello
- 24 Sergi
- 13 Casilla Cortés
- 03 Rodríguez
- 18 Fuentes Hernández Booked
- 14 López Silva
- 06 da Silva Junior
- 15 Moreno
- 07 Bifouma Koulossa (Córdoba - 63' )
- 04 Sánchez Mata Booked
- 09 García de la Fuente
- 23 González Casanova (Lanzarote - 83' Booked )
- 25 Torje
- 01 Parreño Boix
- 05 Tejera
- 11 Capdevila
- 12 Lanzarote
- 19 Colotto
- 22 Fernández Iglesias
- 24 Córdoba
Ref: Carlos Velasco Carballo