Canelo Alvarez now holds four belts and a crown.
He defeated Caleb Plant by TKO in the 11th round on Saturday in Las Vegas to win the IBF belt and become the undisputed super middleweight champion. After the match, King Canelo stood in the ring with all of his hardware, and a crown atop his head.
With Canelo adding the IBF belt to his collection, which also includes the WBC, WBA and WBO titles, the 31-year-old Mexican now holds all four belts in the weightclass.
"This is for everybody, especially for Mexico," Canelo said on SHOWTIME after the match. "It's another one for our team."
Canelo, who improved to 57-1-2 in his career, knocked down Plant after a left hook and right uppercut in the eleventh. Plant got back to his feet but never fully recovered. Canelo swarmed and quickly sent Plant back to the mat, leading to the stoppage and the first loss of Plant's career (21-1).
"That's the way it had to finish," Canelo said. "He was already hurt and I went for the kill."
As he has done with nearly all of his opponents. Canelo defeated Callum Smith last December to win the WBC and WBA belts and knocked out Billy Joe Sauders in eight rounds to win the WBO title in May.
He becomes boxing's sixth undisputed champion, joining Terence Crawford (junior welterweight), Bernard Hopkins (middleweight), Oleksandr Usyk (cruiserweight), Jermain Taylor (middleweight) and Josh Taylor (junior welterweight).
"We're only six," Canelo said. "It makes me happy, very motivated to be one of the six undisputed champions of the world."