The goal was greeted with a wave of protest against the referee and began to protest every decision, such as the one that led to Rossi taking a free kick that Valdes saved low to his left.
The second half started with Barca looking nervous, but Leo Messi put them back in front just before the hour, lifting the ball over Lopez from a tight angle following a quickly taken free kick and an exchange of passes with Pedro.
Barcelona were again in control, but Guardiola opted for caution and replaced Villa with Seydou Keita soon afterwards, while Villarreal brought on winger Jefferson Montero on for Borja Valero.
Messi assured the points after 37 minutes of the second half when he was able to tap Pedro’s deflected shot home from close range, although replays showed that him to be marginally offside.