And having scored the opening goal in a 2-0, two-legged victory over Tigre in the final, Lucas Moura waved goodbye to his old team-mates and joined up with PSG at their winter training camp in Doha, Qatar.
"Choosing PSG is a challenge, a challenge for me," he told reporters. "[Director of football] Leonardo helped me a lot with my decision, and so that I could stay with my old team in Brazil until the end of the season.
"I'm glad to know that Carlo Ancelotti counts on me. I'll try to do my best and give the best for the team. I always tried to be focused on Sao Paulo in the last few months. Now, I can think of PSG, who are a great club. I'm here to offer my assistance to my new team."
The French capital club have enjoyed a number of Brazilian players over the years, including Ronaldinho and Leonardo himself, and the current squad can boast five with Lucas Moura's arrival.
And he is looking forward to adding to a burgeoning legacy now that he has finally joined up with his new team-mates.
"PSG have a long history with Brazilian players and I hope that I can write a new chapter in this story and please the fans," he continued. "Everyone expects a lot from me, but I am very confident.
Lucas Moura will take his first training session with the club on Tuesday afternoon, but is not expected to feature in their friendly against Lekhwiya on Wednesday.