(CNN) -- Samuel Eto'o missed a penalty as Barcelona's title celebrations fell flat on Sunday when they slipped to a 2-1 defeat at Real Mallorca 24 hours after becoming Spanish champions.
Barcelona fans celebrate on the famous Ramblas boulevard after Real Madrid's 3-2 defeat at Villarreal.
Real Madrid's 3-2 reversal against Villarreal on Saturday night handed the Catalan side the Primera Liga crown for the first time since 2006 -- and expectations were high of a showcase of Barca's attacking skills.
Eto'o scored after 10 minutes to set the expected tone but from there on it was a disappointing day as the striker missed a hatful of chances including a last-gasp spot kick.
A fine strike from the impressive Juan Arango and a deft Loureiro Santana header sealed the points for the hosts.
Atletico Madrid moved into fourth place after coming out on top against Valencia as the battle for the final Champions League place continues to go all the way.
Diego Forlan scored the only goal from the penalty spot after 30 minutes after Sergio Aguero had been brought down by visiting keeper Cesar Sanchez to leave Atletico two points clear of Los Che.
At the other end of the table, Sporting Gijon moved out of the relegation zone after an impressive 2-1 victory against high-flying Malaga thanks to an own goal eight minutes into the second half from Helder Rosario.
Gerard handed Sporting a 24th-minute lead with Robson Weligton levelling matters 14 minutes later for a Malaga side whose Champions League hopes are now all but over.
On Saturday Madrid twice came from behind, but goalkeeper Iker Casillas' error in stoppage time gifted Villarreal the victory that ended any lingering title hopes.
Barcelona's focus can now turn to their Champions League final meeting with Manchester United.
Taking the Spanish title is Barcelona's second trophy this season after they secured the Copa del Rey in midweek.
Villarreal denied Pep Guardiola's men the title last weekend as they scored a last-gasp leveller at the Nou Camp, and there was another thrilling climax at El Madrigal, although this time Barca were the beneficiaries of the late goal.
The normally unflappable Casillas dropped a cross at the feet of Joan Capdevila who tapped home the winner at the death.
Gonzalo Higuain had looked to have secured a point for Madrid with an 88th-minute leveller which appeared offside.
Earlier Robert Pires (17) and Ruben Cani (62) twice put the Yellow Submarines ahead either side of a Rafael Van der Vaart equalizer.