Los Blancos, who scored through Cristiano Ronaldo, have now become the joint-most successful team in the history of the competition alongside El Clasico rivals Barcelona.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
REAL: Navas; Carvajal, Ramos, Varane, Marcelo; Casemiro, Modric, Kroos; Isco, Benzema, Ronaldo
GREMIO: Grohe; Edilson, Geromel, Kannemann, Cortez; Michel, Jailson, Ramiro, Luan, Fernandinho; Barrios
2 - Real Madrid might be the first side to be club World Champion in two consecutive years since Sao Paulo under Tele Santana on 1992 and 1993 (Intercontinental Cup). Defiance. pic.twitter.com/4b5Yh2uqdb— OptaJose (@OptaJose) December 16, 2017