Lionel Messi scored twice as Barcelona won for the sixth time in a row against rivals Espanyol.
Atletico Madrid's faint La Liga title hopes look to be over after they lost 2-0 at Athletic Bilbao on Saturday.
Espanyol forward Wu Lei became the first Chinese footballer to score in La Liga, scoring his side's third in a 3-1 win at home to Real Valladolid on Saturday.
Villarreal boosted their hopes of La Liga survival with a 3-0 victory over Sevilla on Sunday.
Karim Benzema's 18th goal of the season set Real Madrid on their way to a 3-0 La Liga victory as they finally wore down a stubborn Alaves.
Rayo Vallecano climbed out of the La Liga relegation zone for the first time this season with a 1-0 win at Alaves on Monday.
Two goals apiece from Jaime Mata and Jorge Molina gave Getafe a comprehensive 4-0 home victory against fellow European hopefuls Alaves.
Borja Baston salvaged a point for Alaves in a 1-1 draw at Girona on Saturday but the visitors missed the chance to move up to third place in La Liga table.
Alaves continued their excellent home form by recovering to beat Valencia 2-1 and move above Real Madrid in La Liga.
Jonathan Calleri scored the only goal as Alaves climbed to fifth in La Liga with a 1-0 win at Real Sociedad, while Girona and Getafe drew 1-1 in the day's other game.
Barcelona moved three points clear at the top of La Liga following an impressive 4-0 win at derby rivals Espanyol.
The latest from the back pages of the European newspapers, including updates on Aaron Ramsey, Alvaro Morata, Manolo Gabbiadini and Nicolas Pepe.
Denis Suarez struck twice for Copa del Rey holders Barcelona as they thrashed Cultural Leonesa 4-1 on Wednesday to progress to the last 16 5-1 on aggregate.
Barcelona returned to the top of La Liga with a comfortable 2-0 victory against Villarreal at the Nou Camp.
Alaves missed the chance to jump to the top of the La Liga table, falling to a surprise 1-0 loss at struggling Leganes.
Sevilla and Alaves moved level on points with Atletico Madrid - and one point behind leaders Barcelona - in La Liga after fighting back for victories.
Alaves missed the chance to go second in La Liga after conceding an injury-time goal in a fiery 2-1 defeat to Basque rivals Eibar.
Surprise packages Alaves are second in La Liga after beating struggling Villarreal 2-1 on Sunday, while Sevilla also won.
Real Madrid's miserable run continued as they slid to a last-gasp 1-0 La Liga defeat at Alaves on Saturday, marking their longest run without scoring in over 33 years.
Alaves spurned the chance to join Barcelona and Real Madrid at the top of La Liga after going down 2-1 at Levante on Sunday.