Real Sociedad is the team that chases Barcelona closest to the league top in Spain.
But during Wednesday's summit, the Basques had no chance against the winning machine from Catalonia.
Fridolina Rolfö's gang won 9-1 and the Swede herself scored the 3-0 goal after less than an hour.
The 28-year-old received the ball to the left in the penalty area and cut with a rock-hard ground shot with the weaker right foot.
Rolfö played left back for 72 minutes before she was replaced.
The win was Barcelona's 21st in the league game in 21 matches with a goal difference of 122-6.