Undisputed champion 'Canelo' Alvarez hands Munguia first defeat
Alvarez handed Munguia the first defeat in 44 professional bouts, dropping the 27-year-old challenger in the fourth round and inexorably taking control to improve to 61-2-2 in his storied career.
The judges scored it 117-110, 116-111 and 115-112 for Alvarez, who retained his IBF, WBA, WBC and WBO belts.
Munguia, whose 34 knockouts included victories inside the distance in four of his previous five fights, came out on the attack.
He pushed back the vastly experienced Alvarez with his jab and rattled the champion in the third round with a right to the jaw.
But Alvarez responded in the fourth. After Munguia connected with a pair of solid rights Alvarez followed a left hook with a massive uppercut that sent Munguia to the canvas.
"You know, I take my time," Alvarez said of his measured start.
"I have a lot of experience. Jaime Munguia is a great fighter. He's strong. He's smart, but I take my time."
The fifth round opened to chants of "Canelo!" ringing in the T-Mobile Arena in Las Vegas, where support was evenly divided between the Mexican combatants in a fight coinciding with Mexico's Cinco de Mayo festivities.
An Alvarez jab popped Munguia's head back and, in the sixth, an Alvarez left hook had Munguia's knees buckling briefly.
In a fight billed as a possible changing of the guard, Munguia -- who has honed his aggressive style under the tutelage of longtime Manny Pacquiao trainer Freddie Roach -- continued to press.
But his vaunted power rarely bothered Alvarez, who repeatedly found a way past Munguia's guard to land the more damaging blows.
Munguia managed to assert himself again in the ninth round, backing the champion up with a flurry of blows to the face before Alvarez responded with more punishing blows to the body.
Munguia seemed to know in the 12th he needed a knockout, but once again it was Alvarez ending the round on the strongest note with another jarring uppercut.
"I have 12 rounds to win the fight, and I did it," said Alvarez, who has recorded 39 knockouts but none since he stopped Caleb Plant in the 11th round in 2021.
Alvarez said that after a few rounds he could see everything that was coming from Munguia.
The best right now
"He's strong, but he's a little slow," Alvarez said. "I can see every punch.
"That's why I'm the best," added Alvarez, who bolstered his claim to title of best pound-for-pound boxer in the world but demurred at the suggestion he's the best fighter in history to come from Mexico.
"When I retire, my numbers will say what position I'm in," he said. "I know there's a lot of great Mexican fighters in the past.
"But I'm the best who's fighting right now," he said.
Munguia could not disagree.
"There's no doubt I would have beaten anyone else tonight," Munguia said.
"Maybe I got a little desperate because I wanted to get the points back and get into the fight and he took advantage of it," he added.
"When he hit me with the uppercut I was more surprised than hurt."
There have been calls for Alvarez next to fight David Benavidez, a three-time WBC super-middleweight world champion who will step up to light heavyweight next month.
"I don't know right now. I'm going to rest and enjoy my family," Alvarez said.
"If the money is right, I can fight right now.
"At this point everybody's asking for everything, right," Alvarez added, pointing to the list of big names he has faced as proof he won't duck anyone.
"I fought all of them and I can do what I want," he said.