PSG has now secured the season-opening cup on 14 separate occasions.
The Parisian giants required a stoppage-time leveler followed by a perfect spot-kick decider to overcome Marseille in the Gulf and capture a fourth straight Trophee des Champions victory.
The European champions appeared to be coasting towards a comfortable win in the showdown between the French league winners and the French Cup holders after the French winger opened the net in the opening stages.
However, the southern French side fired two times late to take a surprise advantage. First, Mason Greenwood scored from the penalty spot, before the defender inadvertently turned the ball into his own net for an own goal.
In a breathtaking twist of fortune, the Portuguese striker grabbed a vital leveler in the dying moments to force the contest into a deciding shootout. The Parisian shot-stopper Lucas Chevalier then emerged as the key figure, stopping crucial attempts from O'Riley and Hamed Traore.
In the shootout, Goncalo Ramos, the midfielder, Nuno Mendes, and the young talent all converted with composure for Paris Saint-Germain to seal a 4-1 shootout win.
The record champions Paris Saint-Germain, who met last season's Ligue 1 runners-up Marseille after completing a league and cup double, have now won this trophy for the 12th time in the past 13 years.
