Paris, June 2 -- There was a carnival atmosphere inside Court Philippe-Chatrier on Monday afternoon as Paris Saint-Germain footballer Ousmane Dembele made a surprise appearance, parading the UEFA Champions League trophy before a packed stadium, shortly after Frenchwoman Lois Boisson's stunning upset win over world No. 5 Jessica Pegula.

Dembele, fresh off PSG's emphatic 5-0 victory over Inter Milan in Saturday night's Champions League final, walked out from the players' tunnel to a rapturous reception, holding aloft the most coveted trophy in European club football.

The scene marked a unique confluence of sporting pride for Parisians, with Boisson delivering one of the shocks of the tournament on home soil and PSG, the city's dominant foot...