Barça started the first official match of Ronald Koeman’s tenure on the front foot, pegging Villarreal back at every opportunity.
An open game saw both goalkeepers called upon in the early exchanges, before Ansu Fati rifled the blaugranes ahead just before the quarter hour from a pinpoint Jordi Alba assist.
Four minutes later, Fati had his second. Philippe Coutinho led a counter from his own half and picked out the Spanish international with plenty of space in the left inside channel, who placed his effort low into the bottom-left corner past Villareal shot-stopper Sergio Asenjo,
Fati was again involved for a goal as he surged past the defender and drew the foul, with the referee pointing to the spot. Messi stepped up and sent the keeper on wrong side to score his first goal in the Koeman era.
Barca had the game wrapped up by half-time as Pau Torres turned Messi’s cross into his own net.