كتب : Sherif Tarek
Pedro Rodriguez wrong footed his marker with a crisp turn seconds past the half-hour mark and scored the winner with a fierce clinical finish from inside the area.
The narrow win is the Catalans' sixth league victory, and now they are leading the way with 18 points.
Barcelona's arch-rivals Real Madrid have also won all their league games thus far.
They will keep pace on top of the table should they beat Sevilla away on Sunday.
Barca and Real, who are expected to compete with each other for the title in a two-horse race till the end of the season, will clash late in November.
Rodriguez's goal