Barcelona opened up a three-point lead over rivals Real Madrid at the top of La Liga on Saturday, defeating Alaves 4-1 thanks to goals from Lionel Messi, Antoine Griezmann, Luis Suarez and Arturo Vidal.
Barca, who drew 0-0 with Madrid at the Camp Nou in El Clasico on Wednesday, opened the scoring 14 minutes in as Griezmann scored his seventh league goal of the season.
The France international found the net with a first-time strike from the edge of the box.
The home side dominated possession throughout the first half as Alaves failed to produce a single shot on target, then doubled their lead on half-time through Chile international Vidal.
Alaves pulled one back shortly before the hour mark, with Pere Pons scoring for the visitors, but their fightback was cut short as Messi curled in his team's third from outside the box.
Messi's strike marked the sixth year in a row he has scored 50 goals in a calendar year.
Suarez completed the scoring with a penalty 15 minutes from time.
Madrid play Athletic Bilbao at the Bernabeu on Sunday and a win would see them draw level with Barca on points.