Barcelona are now in first spot with six points while Osasuna, yet to open their account, sank to the basement of the table.

The Cameroonian gave the visitors no time as he struck the opener as early as the first minute after being set up by Ronaldinho.

Eto'o latched on to a wrong pass from an Osasuna defender and volleyed the ball over the advancing keeper in the 26th minute to double the lead.

Argentina's Messi put the last pin in Osasuna's coffin in the 36th minute when he controlled a low cross from Eto'o inside the area and nipped the ball in between the keeper's legs.