Saul 'Canelo' Alvarez beat fellow Mexican Jaime Munguia by a unanimous points decision to retain his WBA, WBC, WBO and IBF super-middleweight titles in Las Vegas.
Munguia was dropped for the first time in his career in the fourth when he was caught by a right uppercut before Alvarez went on to win on points - the judges scoring the fight 117-110, 116-111 and 115-112.
Alvarez extended his career record to 61 wins, two draws and two losses, while Munguia's unbeaten record was ended in his 44th bout.
"Jaime Munguia is a great fighter. He's strong, he's smart. But I take my time," said 33-year-old Alvarez.
"I have 12 rounds to win the fight and I did. I did really good and I feel proud about it.
"He's strong but I think he's a little slow. I could see every punch. That's why I'm the best. I'm the best fighter right now, for sure."
Munguia had won all his previous 43 fights, with 34 being by knockout, before facing Alvarez.
“I came out well," said the 27-year-old. "I think at the beginning I was winning some of those rounds.
"It was going well, I let my hands go but he’s a fighter with a lot of experience. Unfortunately, he beat me. It definitely hurts."
BBC