Villa, who missed the second half of last season and Euro 2012 after breaking his leg in December, netted after appearing as a late substitute to complete the win as Barca showed it was business as usual despite this summer's departure of record-breaking coach Pep Guardiola.
Lionel Messi struck twice, Carles Puyol and Pedro also getting on the scoresheet.
Barca coach Tito Vilanova said afterwards: “it’s important to start off on the right foot. There are a lot of positive things to be learned from tonight’s match. We played 90 minutes with a lot of intensity. In the first 15 minutes we were strong and we reacted well to their equaliser. Furthermore, Villa returned and he scored a goal.” On the forward, the manager said that the goal “gives the player a lot of morale.”