Barcelona's Sunday celebrations started early with a 6-1 romp over Getafe, and ended late with a slip-up by second-placed Atletico Madrid which has all but ended the Spanish title race.
Atletico's 2-1 defeat at Rayo Vallecano gave Barca a commanding 12-point lead with 15 matches to play, as third-placed champions Real Madrid languish another four points adrift.
"It was an unusual time to play but we had a party in the stadium," the Catalan side's assistant coach Jordi Roura said after the midday kickoff at the Camp Nou, where more than 85,000 fans turned up.
"The players were at an extraordinary level. They were intense from the first minute," added Roura, who is running the team while Tito Vilanova is receiving cancer treatment in New York
Alexis Sanchez opened the scoring in the sixth minute with his first league goal this season before Lionel Messi netted for a record-extending 13th successive La Liga game before quarter of an hour had been played -- his 35th in the competition from 23 appearances.
David Villa and substitute Cristian Tello scored in the second half before Getafe hit back through striker Alvaro Vazquez, but then Andres Iniesta and defender Gerard Pique netted in time added on.
"We felt great on the pitch, a lot of people were able to make it to the stadium and the atmosphere was fantastic," Pique said.
"It wouldn't be an inconvenience if we had to play at the same time in the future."
Atletico striker Radamel Falcao scored his 19th league goal this season, putting him third in the Pichichi standings behind Real's Cristiano Ronaldo -- who took his tally to 24 with a hat-trick in Saturday's 4-1 win over Sevilla.
However, it came far too late -- the last kick of the match -- as Vallecano moved up to fifth place on goal difference above Valencia thanks to first-half goals from Guinean striker Alhassane Bangoura and Brazilian forward Leo Baptistao.
Real Sociedad moved up to eighth with a 2-1 win at Zaragoza, while Barcelona's city rivals Espanyol eased relegation worries with a 4-0 win at Athletic Bilbao.
Mario Balotelli scored his second successive penalty for AC Milan to rescue a 1-1 draw at Cagliari, but his team surrendered fourth place in Serie A to city rivals Internazionale.
Balotelli took his tally to three goals in two games since signing for $30 million from English champions Manchester City with an 82nd-minute spot-kick, but the Italy striker also missed a late chance to snatch victory.
Inter won 3-1 at home to Chievo to move within a point of third-placed Lazio, as striker Antonio Cassano scored in the second minute then defender Andrea Ranocchia restored the lead with a header after Luca Rigoni's equalizer, and Diego Milito added the third in the second half.
Freiburg moved up to fifth in the Bundesliga following Sunday's 1-0 win at home to lowly Fortuna Dusseldorf.
An 87th-minute goal from Czech player Pavel Krmas put Freiburg above Mainz and Hamburg on goal difference.
Mainz drew 1-1 at second-bottom Augsburg, while Hamburg crushed second-placed defending champions Borussia Dortmund 4-1 on Saturday.
Lyon's title hopes suffered a blow in Sunday's 3-1 home defeat by Lille, which meant Paris Saint-Germain ended the weekend with a six-point lead.
Third-placed Marseille also dropped points, drawing 1-1 at Evian -- who moved out of the bottom three on goal difference.
PSG beat Bastia 3-1 on Friday, with star striker Zlatan Ibrahimovic scoring a penalty for his leading 21st goal this season.