Messi opened the scoring but while Francisco Montanes brought Zaragoza level, Alex Song restored the advantage before the break.
Messi got his second and his 17th of the season to ensure a victory and another record with Barca’s start beating those of Real Madrid in the 1968-69 and the 1991-92 seasons.
“It was an excellent performance from the team and Leo is a key player but he doesn’t do it on his own and has great players around him,” said Vilanova afterwards.
Madrid have an uphill task to now catch Barca but the ease with which they took apart Athletic suggests they are on the right track.
A deflected shot from Karim Benzema off Jon Aurtenetxe put them ahead and then Sergio Ramos and Benzema again gave them a commanding lead. Ibai Gomez reduced the arrears before the break but Mesut Ozil and Sami Khedira made it a heavy defeat for sorry Athletic.