The visitors held firm at the Nou Camp until four minutes after the break when Messi opened the scoring and Samuel Eto'o doubled the lead just four minutes later.

Jose Barkero grabbed one back just after the hour mark, but Thierry Henry restored the two-goal cushion after 71 minutes and Messi made it four at the second attempt with 14 minutes remaining.

The win extended Barca's lead at the top of La Liga to 15 points from Real Madrid and Sevilla, who tomorrow face Deportivo La Coruna and Racing Santander respectively.

In today's other game, a howler from Pascal Cygan gifted Osasuna a vital point in their battle against the drop as they drew 1-1 with Villarreal at El Madrigal.

The former Arsenal defender fluffed a routine clearance in his own six-yard box, presenting the chance for substitute Dady to cancel out a first-half strike from Guiseppe Rossi.

The Yellow Submarine will probably feel they did enough to win the game but they were denied on numerous occasions by the excellent goalkeeping of Roberto.