Barcelona's Alcantara celebrates after scoring a goal against Villarreal during their Spanish first division soccer match. Picture - Reuters.

Barcelona began their defence of the Spanish league title with a typically dominating 5-0 win against Villarreal at the Nou Camp.

On Sunday, Real Madrid thrashed Real Zaragoza 6-0 and Barca could not afford an early slip-up against Villarreal, who are widely touted to come good this season.

Typically, Pep Guardiola's side dominated from start to finish with emerging midfielder Thiago Alcantara (25th) and new-signing Cesc Fabregas (45th) both scoring in the first half.

Fellow new-signing Alexis Sanchez made it 3-0 two minutes into the restart before Lionel Messi got into the act with also marked his debut with a goal before Lionel Messi grabbed two for himself in the 54th and 72nd.