The celebratory mood which had accompanied the handover of the championship trophy from Spanish Football Federation chairman Angel Maria Villar turned monentarily into a damp squib as Barca found themselves two goals adrift before Ronaldinho and Ludovic Giuly saved their blushes.

After early Barca pressure it was Villarreal who went in front with a superbly-executed 14th-minute drive from Diego Forlan, having a tremendous season in Spain after a miserable time with Manchester United, whom he left last summer.

Barca's Cameroon international striker Samuel Eto'o then drove a 20th-minute spotkick against the underside of the bar after Quique Alvarez had brought the African down in the box.

Eto'o was looking to add to his tally of 25 league goals at start of play to ensure he wins the 'pichichi' title of La Liga's top marksman.

Instead, that chance went begging and Forlan instead moved his total onto 22 from the penalty spot after young Barca defender Oleguer Renom fouled Jose Mari in the 29th minute for 2-0.

Ronaldinho headed in a Juliano Belletti cross from the right in the 32nd minute to bring renewed hope in the stands, which before kickoff had been smothered with "Barca, Barca, Barca" posters.

Another poster greeted the title win as being as significant as a papal election, bearing the legend: "White smoke - habemus Liga," for the first time in six seasons.

Barca, who left keeper Victor Valdes, just 26 goals conceded all season, on the bench to hand Albert Jorquera a rare start, then pulled level after 35 minutes when Ludovic Giuly scrambled home from close range.

Three minutes after the break, Giuly blasted home his tenth goal of the season to put the hosts finally in front, only for Forlan to complete an impeccable hattrick with a cute lob on 70 minutes.

The effort means the Uruguayan can yet draw level in the scoring stakes with Eto'o if he hits a double on the final day next week against Levante.

Earlier Sunday, Mallorca kept their hopes of survival alive with a storming 3-0 win at midtable Deportivo La Coruna.

The win moved the Balearic Island side out of the bottom three with just one match to go following a victory achieved with goals from Francisco Farinos and Juan Arango before the interval and Japanese international striker Yoshito Okubo 18 minutes after the break.

Mallorca moved a point clear with 38 points to Levante's 37 after a win at the Riazor stadium which gives Hector Cuper's men hope of avoiding the dreaded drop. Levante, who six weeks ago were 11 points clear of the Mallorcans, could only draw with Valencia.

On Saturday, one of Villarreal's rivals for a top four placing, Real Betis, beat Real Zaragoza 3-2 but are a point adrift of Villarreal.

Third and fourth place will be enough for a qualifying round spot in Europe's hugely lucrative top club competition.

Should Betis and Villarreal make it, they would have made the most of the disappointing seasons of traditional European qualifiers in Valencia, Deportivo La Coruna and Atletico Madrid.

Elsewhere Sunday, Seville saw their hopes of overhauling Villarreal, whom they trail by two points, and Betis take a knock after their goalless draw at modest-but-safe Getafe.

On Saturday evening, Atletico Madrid drew 0-0 at city rivals Madrid in a meaningless match for both teams, with Real assured of second spot and an automatic berth into the Champions League and Atletico in midtable.