Douglas Luiz helped Brazil get their Olympic campaign off to a winning start on Thursday.
The midfielder played 90 minutes as his country beat Germany 4-2 in a rematch of the 2016 gold medal match, which Brazil also won.
A hat-trick from Richarlison had Brazil 3-0 up at half-time before Germany, who had Maximillian Arnold sent-off, hit back through Nadiem Amiri and Ragnar Ache.
And despite a nervy finish, Paulinho wrapped up the win with a fourth in stoppage time.
Brazil's defence of their gold medal continues against Ivory Coast on Sunday.
