The Cameroonian striker scored his 26th goal of the season in the 38th minute to put Barcelona, already crowned League and European champions, ahead and outscore Valencia's David Villa.

Bilbao, who are safe from relegation and far from European actions next season, took advantage from playing an experimental Barca side and scored three times after the break.

Fernando Llorente equalized in the 58th minute before Felipe Gurendez put his side ahead in the 78th minute. Barcelona defender Oleguer converted the ball into his own net three minutes later to seal Bilbao's victory.

Eto'o has been denied the top-scorer's title last season when he finished the campaign with 25 goals, just one goal behind Villarreal's Diego Forlan.