Lionel Messi scored a record-breaking 24th Primera Division hat trick and Luis Suarez hit a brace as Barcelona beat Rayo Vallecano 6-1 at the Camp Nou to return to the top of the table in emphatic style.
The Uruguayan got the ball rolling with an early goal and Gerard Pique doubled the lead shortly after the break, before Messi scored a treble inside 12 minutes which took him one hat trick clear of Cristiano Ronaldo.
Both sides had their right-backs sent off, with Tito getting two yellow cards for Rayo and Dani Alves getting a straight red for bringing down Alberto Bueno, who scored a consolation goal for the visitors, only for Suarez to pounce again in stoppage-time.
This was a merciless performance from Luis Enrique's side, who go one point clear at the top of the table after Real Madrid lost at Athletic Bilbao on Saturday, reclaiming top spot for the first time in 2015.
And Messi's hat-trick -- his sixth of the season -- takes him level with Ronaldo at the top of the league's scoring charts with 30 goals from 25 starts.
A late headed goal from Shkodran Mustafi salvaged a 1-1 Primera Division draw for Valencia at the Vicente Calderon and further dented Atletico Madrid's title hopes.
Koke's piledriver had given the champions the lead in the first half but - with 12 minutes remaining - Germany defender Mustafi pounced on the rebound following a free-kick to hand a lifeline to Valencia, who had midfielder Javi Fuego dismissed in injury time for picking up two quick-fire bookings.
The draw means Atletico remain third in the La Liga table and one point above Sunday night's opponents, but the Rojiblancos slip seven points behind new league leaders Barcelona.
Atletico had both centre-back Miranda and top scorer Antoine Griezmann out suspended, so Fernando Torres made just his third league start since returning to the club, while Mario Mandzukic was again left out of Diego Simeone's starting line-up, and Koke made his first start in a month after recovering from a hamstring injury.
Valencia meanwhile were boosted as Nicolas Otamendi made a speedy recovery from an ankle injury sustained in last week's win over Real Sociedad.
Villarreal overcame Celta Vigo to win 4-1 and record an eighth straight home win in the Primera Division.
Giovani dos Santos opened the scoring in the 40th minute and Mateo Musacchio tightened the hosts' grip on the game just before the break.
Augusto Fernandez got Celta back into the game shortly after the re-start but Luciano Vietto and Gerard Moreno both scored in the closing stages to put the game out of the Galicians' reach and bring their five-game unbeaten run to an end.
With his side having played eight games in the last month - and the first leg of a Europa League tie with Sevilla to come on Thursday - Marcelino predictably rotated his squad after the 3-1 Copa del Rey semi-final defeat to Barcelona on Wednesday, again starting without Denis Cheryshev and Vietto and handing starts to Moreno and Giovani.
His opposite number Eduardo Berrizo made just one change from the team that drew 1-1 with Elche last week, replacing the injured Michael Krohn Dehli with Sergi Gomez and playing an open 3-4-3 formation.
A mistake by Espanyol goalkeeper Kiko Casilla proved to be costly as it set up Sergio Canales for the only goal of the game which saw Real Sociedad win 1-0 at Anoeta on Sunday.
Casilla's clearance in the 38th minute fell directly into the path of Canales, who gratefully accepted the gift and put David Moyes's side ahead.
It proved to be the decisive goal as despite an entertaining game, neither side was able to find the target again.
The result lifted La Real to 11th place in the overall Primera Division standings.