PSG has now won the prestigious cup on 14 separate times.
The Parisian giants needed a stoppage-time equaliser followed by a perfect penalty shootout to get past Marseille in Kuwait and capture a fourth straight Trophee des Champions victory.
The Champions League holders seemed to be sailing towards a comfortable triumph in the match between the French league winners and the Coupe de France winners after Ousmane Dembele found the net in the opening stages.
Yet, the southern French side fired twice in the closing moments to take a surprise lead. First, the English forward converted from the penalty spot, before Willian Pacho inadvertently directed the ball into his own net for an own goal.
In a remarkable turn of fortune, Goncalo Ramos snatched a crucial leveler in the dying moments to force the contest into a deciding shootout. PSG goalkeeper Chevalier then emerged as the key figure, saving crucial kicks from O'Riley and Traore.
From the spot, Ramos, Vitinha, Nuno Mendes, and Desire Doue all scored with composure for PSG to complete a 4-1 penalty win.
The record champions Paris Saint-Germain, who met last season's Ligue 1 runners-up Olympique de Marseille after completing a league and cup double, have now won this trophy for the twelfth time in the last 13 years.
