Former Valencia striker Jonas got off the mark for Benfica on his debut.
The Brazilian was released by the La Liga side on deadline day, sparking a reported scramble for his signature as a free agent.
Among the teams linked with him, reported The Mail, were Premier League side Tottenham Hotspur.
Roberto Soldado's former strike partner, the 30-year-old eventually signed with Benfica.
He came on at half-time in a Primeira Liga contest with Arouca, and scored late in the game to extend a lead to a 4-0 victory.