The Parisian club has now won the prestigious cup on 14 separate times.
The Parisian giants needed a stoppage-time leveler followed by a successful penalty shootout to get past Marseille in the Gulf and capture a fourth straight Trophee des Champions title.
The Champions League holders appeared to be coasting towards a comfortable win in the showdown featuring the Ligue 1 winners and the Coupe de France holders after Ousmane Dembele opened the scoring early on.
Yet, the southern French side fired two times in the closing moments to take a shock lead. First, Mason Greenwood converted from the penalty spot, before Willian Pacho inadvertently directed the ball into his own net for an own-goal.
In a remarkable twist of fortune, Goncalo Ramos grabbed a crucial equaliser in the final seconds to send the match into a penalty shootout. The Parisian shot-stopper Lucas Chevalier then stood as the hero, saving crucial attempts from Matt O'Riley and Traore.
From the spot, Goncalo Ramos, Vitinha, the full-back, and the young talent all converted with composure for Paris Saint-Germain to seal a 4-1 shootout win.
Now 14-time winners PSG, who faced last season's Ligue 1 runners-up Olympique de Marseille after achieving a league and cup double, have now won this competition for the twelfth time in the past thirteen years.
