The fight, held at the MGM Grand Garden Arena, ended with Alvarez's victory by knockout in the 11th round.
For 36-year-old Kovalev, this is the fourth loss of his career; he has had 34 wins (29 by knockout) and one draw. The 29-year-old Alvarez has 53 wins (36 by KO), one defeat and two draws.
The Mexican boxer became the world champion in the fourth weight category. Alvarez has won the WBA (Super) and WBC middleweight titles, the WBA regular middleweight title and the WBO light heavyweight title.
Alvarez will take home the $35 million prize for this fight, while Kovalev will get three million.
Social media users had different reactions to Alvarez’s victory.