Lionel Messi's hat-trick sparked Barcelona into life as they came from behind to thrash Espanyol 5-1 in the Catalan derby.
A day after Cristiano Ronaldo set a new Primera Division record for hat tricks with 23, Messi grabbed one of his own to move up to 21 himself and secure local bragging rights for Barca in Catalonia.
Messi came to the rescue on the stroke of half-time to cancel out Sergio Garcia's opener for Espanyol, before adding his second five minutes later.
Gerard Pique made it three goals in eight minutes to put Barca firmly in control before Pedro added gloss to the scoreline and Messi turned it into a rout.
The win means that Barca, who also saw Real Madrid equal their record of 18 consecutive wins after their 3-0 triumph over Celta Vigo on Saturday, remain two points behind Los Blancos at the top of La Liga.
David Moyes suffered a humiliating first defeat as Real Sociedad coach as his team were overwhelmed 4-0 by a rampant Villarreal.
The visitors withstood the pressure until the 63rd minute when Bruno Soriano's free kick came off the underside of the bar and bounced off the body of goalkeeper Enaut Zubikarai to roll into the net.
Denis Cheryshev added a second for Marcelino's men 10 minutes later and then substitute Moi Gomez scored two goals inside six minutes to make it 4-0 and pour more misery on Moyes, who had guided his troops to three clean sheets in his previous three games in charge of the Basques.
Alvaro Negredo scored his first goal for Valencia but it was enough as Granada scored a late equaliser to salvage a 1-1 draw.
Negredo seemed to have snatched the win for fifth-placed Valencia with a goal in the 83rd minute, but Valencia lost Paco Alcacer to a direct red card for hitting an opponent before Granada's Isaac Success levelled in the 89th.
Ten-man Sevilla held on to win 1-0 at Rayo Vallecano.
An early strike from Carlos Bacca was enough for Champions League chasing Sevilla, who had midfielder Daniel Carrico sent off for a second bookable offence three minutes from time.
It was hardly a surprise that the visitors ended the game a man light after picking up six bookings during the 90 minutes.
Information from The Associated Press was used in this report.