Barcelona made it six wins out of six in La Liga with victory at Catalan neighbours Girona.
Barca's first two goals came from own goals by the hosts, who are in their first La Liga season.
Aday Benitez deflected Jordi Alba's shot into his own net and keeper Gorka Iraizoz turned Aleix Vidal's cross into his own net.
Luis Suarez smashed home the third after latching on to a Sergi Roberto long ball.
Girona, who are co-owned by Manchester City, played five City loanees in the game, with Brazilian midfielder Douglas Luiz impressive in attacking positions.
Pablo Maffeo, in his third season on loan, successfully man-marked Barca's Lionel Messi, who had scored 11 goals in his previous five games, including four against Eibar on Tuesday.
Barcelona, who had been expected to have a difficult season after losing boss Luis Enrique and striker Neymar, travel to Sporting Lisbon in the Champions League on Tuesday. They won their opening group game 3-0 against last season's finalists Juventus.
There were pro-Catalan independence chants throughout the game at Girona's 13,000-capacity Montilivi stadium.
Both clubs this week issued statements backing the proposed independence referendum scheduled for 1 October, which the Spanish government is trying to block.
Earlier on Saturday, Real Madrid beat Alaves 2-1 as Dani Ceballos scored twice, and Atletico Madrid saw off Sevilla 2-0.