© Getty Images
The hosts started the game positively, as veteran striker Zlatan Ibrahimovic tested Saint-Etienne goalkeeper Stephane Ruffier with an effort from inside the area, before Edinson Cavani missed the target from a corner.
PSG took the lead on 23 minutes through left-back Kurzawa, who skipped past Francois Clerc on the left flank before producing a clinical finish past Ruffier.
Ibrahimovic missed a good opportunity to double his side's lead on the stroke of half time, as Angel di Maria found the striker with an inviting right-wing cross, but the former Barcelona man headed over the bar.
After the break PSG continued to control the match, and doubled their lead on 48 minutes as Cavani completed a swift counter-attack with a clinical finish from inside the box.
The hosts added a third goal on 67 minutes, as Cavani found Ibrahimovic inside the Saint-Etienne box, before the club's record goalscorer finished past Ruffier.
PSG wrapped up the victory with a fourth goal before the final whistle, however, as Verratti found substitute Lucas Moura, who headed into the bottom corner of the Saint-Etienne goal.