MADRID - FC Barcelona have to wait another week before they celebrate the BBVA Primera Liga title, as a last minute equalizer from Athletic Club Bilbao midfielder Ander Herrera denied them a win in the historic San Mames Stadium on Saturday.

Among the disappointment, Barca can take positives from the game such as a stunning 30 minute cameo from Leo Messi, who confirmed his return to fitness with a goal and an assist.

Barcelona's Lionel Messi shoots the ball past Athletic Bilbao defenders to score during their Spanish first division soccer match at San Mames stadium in Bilbao, April 27, 2013.[Photo/Agencies]

Barca kicked off knowing a win could see them crowned as league champions if Real Madrid lose away to Atletico Madrid, but also aware that they have the return leg of their Champions League semifinal at home to Bayern Munich on Wednesday.

Although the 4-0 defeat from the first leg leaves little room for optimism in that field, coach Tito Vilanova had spoken on Friday of his side's obligation to give everything to try and overturn that result and at least try and win.

Nevertheless, he included what could be his first choice defense for the game, along with Xavi Hernandez, while Leo Messi was named among the substitutes.

Barcelona's Lionel Messi passes Athletic Bilbao's Mikel San Jose during their Spanish first division soccer match at San Mames stadium in Bilbao, April 27, 2013.[Photo/Agencies]

Athletic meanwhile still need points in order to climb away from the degradation zone and started the game purposefully, looking to pressure Barca high up the field and use the pace of Iker Muniain and Markel Susaeta.

Aritz Aduriz was inches away from opening the scoring after just five minutes as he failed to connect with an Ander Herrera cross, but Alexis Sanchez was unlucky to see his right foot shot bounce off the pace of the post 15 minutes later.

Barca were beginning to control the game, all be it without their usual fluency and Alex Song and Xavi both went close, before Susaeta scored the first goal of the game. Aduriz found space and the winger was on hand to tap in from close range.

It could have been 2-0 just before the break, but Aduriz's header went over the bar, before at the other end, Cesc saw a shot flash across the face of goal.

The second half continued in a similar vein with Athletic struggling to find each other with their passes, but defending well, with Borja Ekiza and Carlos Gurpegui both working hard.

Everything changed when Messi came into the game as a 58th minute substitute, way below his best in Munich as the result of a hamstring injury, Messi needed just 10 minutes before scoring a wonder goal in which he beat three defenders in five meters before clipping home from the edge of the area.

Two minutes later Messi set Alexis Sanchez up for Barca's second with a header than Alexis controlled on his chest before firing into the net.

Athletic struggled to get back into things after the double setback, but the decision to put Ibai Gomez and Fernando Llorente into the game proved decisive as Llorente flicked Ibai's cross into the stride of Ander Herrera who rifled a left foot shot past Victor Valdes to put Barca's title celebrations on hold for a week.