Two goals in three minutes earned the French side a deserved victory over the struggling Portuguese, who are now bottom of the group with just one point from three matches.
After a laboured start Vahid Halilhodzic's PSG side played some neat football and Charles-Edouard Coridon scored the club's first goal in this season's competition on the half-hour mark with Portugal's Pedro Pauleta adding a second two minutes later.
PSG are third in the stadnings with three points behind leaders Chelsea who have a maximum nine points and CSKA Moscow, who the London club beat 2-0 at Stamford Bridge, with four.