The Brazilian scored for the first time in the Primera Division on Tuesday, though he stressed that the win was more important
The Blaugrana went ahead in the fifth minute thanks to the Brazilian, who then assisted Lionel Messi for the second goal before Sergio Busquets made it 3-0 halfway through the first 45 minutes.
Gerardo Martino's men eased up in the second half, with Alberto de la Bella scoring a consolation for the visitors before substitute Marc Bartra adding a fourth for Barca with full-time looming.
"I'm very happy with my first goal in the Liga," the 21-year-old is quoted as having told reporters after the match. "The win was more important though. It may not have been a really nice goal, but the main thing is it went in!
"Messi and I understand each other better each day. He's a genius.
"I'm not suffering from too many fouls, it's normal, it's part of the game."
Barcelona have never won their first seven games of the season but can break their own record of six consecutive victories by beating Almeria on September 28 in their next match.