Barcelona's championship party was gatecrashed by humble Real Mallorca who stunned the double winners 2-1 with two late goals. Samuel Eto'o, who missed a late penalty that would have salvaged a point, had headed Barça ahead with his 29th goal of the season after just ten minutes at the Ono Stadium, but a Juan Arango free-kick [73 min] and Cleber Santana header  secured a comeback win.
Barcelona had won their 19th league title on Saturday when Real Madrid lost 3-2 at Villarreal and Mallorca players saluted the champions with a guard of honour to mark their visitors' achievement of securing a league and cup double for the first time since 1998.
With one eye on the UEFA Champions League final against Manchester United on 27 May, coach Pep Guardiola rested key players Lionel Messi, Xavi, Carles Puyol and Victor Valdes. In came youth players such as Pedro Ledesma, 21, midfielder Xavi Torres, 22, and 19-year-old goalkeeper Oier Olazabal.
However, it was one of Barça's star performers who stole the limelight with old boy Eto'o sending in a bullet header in off the underside of the crossbar in the tenth minute after a great cross from Bojan Krkic. Eto'o made his name at Mallorca in four glorious seasons before joining Barcelona in 2004 for 24 million euros.
It was a 29th goal of the season for Eto'o, taking him two ahead of Diego Forlan in the Pichichi race for the league's top-scorer. No player has reached 30 goals since Brazilian great Ronaldo scored 34 with Barcelona in 1997 and Eto'o is just one short of breaking the 30 barrier.
Eto'o could have had a hat-trick in the first half, but found Miguel Moya on top form in the Mallorca goal. Arango drilled home a free-kick in the 73rd minute to equalise and five minutes later Santana flicked in a header. Eto'o missed a spot-kick in the dying seconds to wrap up his night.
"Eto'o scored a great goal and had his chances, including the penalty miss, but I can't fault him as he has scored goals all season and will continue to do so," said Barcelona coach Pep Guardiola.
"I can't reproach the team at all. We had a lot of players who had not played much and they had to tonight," he said.
The defeat means Barça - currently on 86 points with two games left - can now only equal Real's all-time record of 92 points set back in 1997, although there were 42 games in a season compared to the current 38. Barça are also gunning for Real's goals record of 107 set back in 1990 and need three goals to equal the mark.
"With other players I would not be a champion, but they certainly would be with another coach," said Guardiola. "I appreciate the praise, but it is the talent of the players and their humility to work hard that has taken us this far."
Elsewhere, Atletico Madrid and Valencia are facing off at the Vicente Calderon in a UEFA Champions League qualifying duel.