Malcom showed his strength in extra-time to give Brazil a 2-1 win over Spain and a second straight men's Olympic football gold medal on Saturday.
The Zenit St Petersburg player shrugged off defender Jesus Vallejo too easily and slotted home on 108 minutes, despite the best efforts of goalkeeper Unai Simon.
Brazil, who beat Germany on penalties for their first Olympic men's title in Rio five years ago, had an experienced side like Spain with veteran Dani Alves among those complementing the under-23 side.
Hertha Berlin forward Matheus Cunha put Brazil ahead on the stroke of half-time in Yokohama and they should have already been in the lead but for Richarlison's penalty miss.
The Everton forward then hit the bar in the second half before Mikel Oyarzabal, who like Simon was also part of Spain's Euro 2020 squad, levelled on 61 minutes with a superb volley.
Spain substitute Bryan Gil then rattled the woodwork from distance with a minute left of normal time.
Malcom had the final say however with Spain having a penalty appeal waved away minutes later.
Brazil's Matheus Cunha celebrates scoring. Photo: Rodrigo Reyes Marin/dpa.