The Brazil forward scored within three minutes of his introduction in the second half of the 5-0 win, maintaining his record of scoring on his first appearance for every team
The 23-year-old took just three minutes to find the back of the net after taking to the field as a second-half substitute, and was thrilled to have hit the ground running following his €15 million switch from AC Milan last month.
"The whole team did great today. The first phase of my preparation is done. I know I still have to improve, but I'm really calm and I'm sure that lots of good things will happen along with the team and the fans," he told reporters.
"I've had good results in all of my first matches for a team, be it Internacional, Milan or the Brazil national team, and today was no different. I want to keep working and showing my value.
"I only think about playing football, in doing what I know to help the team. The fans screaming my name helped a lot. I only have to thank the fans."
Pato joined the Club World Cup champions in January in a bid to reignite his career after his spell in Italy was blighted by a series of injuries.