Cameroon's Samuel Eto'o Fils scored twice for Barcelona

But his match did not start well when a shocking back pass from the Cameroonian after 14 minutes put David Villa in the clear and the Zaragoza striker made no mistake to put the visitors ahead.

But the Cameroon captain then made amends in ample fashion by getting two goals to get Barca back in front.

Eto'o restored Barca to level terms 12 minutes after his mistake with a piece of individual brilliance, trapping a long ball forward on his chest and then taking three touches before unleashing a right foot thunderbolt from the edge of the area.

His second strike was less spectacular but equally effective, finding the net from close range just one minute into the second half, connecting with a Ronaldinho cross from wide out on the left.

Spanish international Xavi Hernandez emphasised Barca's dominance after their early scare by cracking home their third from 25 years after 67 minutes.

Giovanni van Bronckhurst completed the rout, the Dutch defender getting a rare goal 12 minutes from time.

The win preserved Barcelona's unbeaten record and moves them up to second place, with 10 points from four games and just behind Valencia on the number of goals scored.