Having missed the opening five matches of the season due to a virus, the defender has since netted three times in six outings after replacing the injured Thiago Silva.
The Brazilian scored against Toulouse in Ligue 1 in between goals in the Champions League against Olympiacos and Benfica.
"I didn't know I could do that. In youth teams, I scored some goals, but since I turned pro, be it at Corinthians or Roma, I had never scored," Marquinhos told reporters.
"It's magical what's happening with PSG. Right from my first game, despite not having played for four months, I scored my first goal.
"It's a moment I'm going to remember forever. And then, almost straight after, I scored two more important goals."
PSG return to action this weekend when they face Bastia at Parc des Princes.