LAS VEGAS -- The boisterous, surprising support for Jaime Munguia was swiftly extinguished with a patented Canelo Alvarez combination on Saturday, a left hook followed by a right uppercut that planted the challenger on the canvas for the first knockdown of his 44-fight career.

Alvarez, boxing's top star, continued to build momentum after that fourth-round knockdown and won the fight with his cleaner, sharper, harder shots to retain his undisputed super middleweight championship in an all-Mexican battle on Cinco de Mayo weekend before 17,492 at T-Mobile Arena.

Alvarez's fourth successful defense of his four 168-pound titles was made official via scores of 115-113, 117-110 and 116-111. ESPN scored it 118-109. This was the third consecutive fight that Alvarez (61-2-2, 39 KOs) scored a knockdown. He also dropped Jermell Charlo and John Ryder in decision wins last year.

"I'm very proud that all the Mexicans are here watching us," Alvarez, ESPN's No. 4 pound-for-pound boxer, said. "... He's a great fighter. He's strong, he's smart. ... But he's a little slow. I can see every punch. Sometimes he got me because I get so confident. ... I did really good and I feel proud about it. ... I'm the best fighter right now for sure."

Munguia, the former junior middleweight titleholder, was competing on the elite level of the sport for the first time. And he no doubt acquitted himself well. The 27-year-old from Tijuana fought with passion and showed an improved jab in his second fight with Hall of Fame trainer Freddie Roach.

The pressure and aggression of Munguia was effective over the first two rounds, but Alvarez eventually timed his opponent, as he usually does. "I take my time," Alvarez said. "That's why I have a lot of experience. ... I have 12 rounds to win the fight and I did."

Munguia (43-1, 34 KOs) won three rounds unanimously: the opening frame along with Rounds 3 and 9. He boxed well, but his punches never appeared to have enough pop to gain Alvarez's respect.

Even when Munguia would pin Alvarez on the ropes and unload, Alvarez was able to evade most of those punches and then return a single shot that backed the challenger up. Then came the knockdown in Round 4, and Munguia's legs never seemed to recover. The experience disparity was clear, too, with Alvarez a first-ballot Hall of Famer who has shared the ring with practically all the top names around his weight during his run.

"I came out strong and was winning the early rounds," Munguia said through an interpreter. "I let my hands go, but he's a fighter with a lot of experience. The loss hurts because it's my first loss and I felt strong. There's no doubt I would have beaten anyone else tonight. ... He's a fighter who creates a lot of problems."

Down the stretch, Alvarez was able to stun Munguia on several occasions, turning his aggression against him. Alvarez's elite counterpunching ability, more powerful punches and ability to evade were all too much to overcome for Munguia. But all is not lost.

Alvarez, 33, credits the first loss of his career, a 2013 defeat to Floyd Mayweather as a 20-year-old, as the performance that helped build him into an all-time great.

Munguia, ESPN's No. 4 super middleweight, entered the ring on the heels of his career-best victory, a ninth-round TKO of Ryder in January. Munguia's previous outing was named ESPN's 2023 Fight of the Year, a bout vs. Sergiy Derevyanchenko where a final-round knockdown earned Munguia the decision.

Alvarez hasn't finished a fighter inside the distance since he defeated Caleb Plant in November 2021 to become undisputed super middleweight champion.

"I'm glad that I gave him this opportunity," said Guadalajara's Alvarez, who closed as a minus-550 favorite on ESPN BET. "Munguia is a great guy and a great champion. He's going to have a great career."

The promotion was overshadowed by the renewed feud between Alvarez and his former longtime promoter, Hall of Fame boxer Oscar De La Hoya. For the first time since November 2019, Alvarez and De La Hoya, Munguia's co-promoter, shared a stage during fight week, and Wednesday's news conference erupted as time did little to soothe old wounds.

De La Hoya took aim at Alvarez and mentioned his failed doping test ahead of his 2018 rematch with Gennadiy Golovkin. Alvarez responded that De La Hoya steals from fighters and referenced GGG, who sued Oscar's Golden Boy Promotions in 2022 seeking upward of $3 million he believed was owed from that rematch.

De La Hoya told ESPN that GGG was paid every dollar due to him and the following day sent Alvarez a cease-and-desist letter demanding that he retract his "defamatory allegations."

Alvarez's attorney, Gregory M. Smith, told ESPN that Alvarez "said what he said."

Alvarez acknowledged that he was more determined to win following the proceedings, and while he didn't finish Munguia inside the distance, he indeed won once again in dominant fashion.

"I've always said [Canelo is] a good fighter in the ring, but this experience for Jaime will just take him to another level," De La Hoya said. "It's just like Mayweather and Canelo. ... Canelo got schooled and then he became the face of boxing."

Now, the cries for Alvarez to fight David Benavidez will return once more as Alvarez prepares for his expected return on Mexican Independence Day weekend in September.

"If the money's right ... I can fight [Benavidez] right now," Alvarez said. "I don't give a s---. It's only a matter of money at this point. Everybody is asking for everything.

"When I fought [Erislandy] Lara, Austin Trout, Miguel Angel Cotto, [Floyd] Mayweather, Billy Joe Saunders, GGG, everybody said I don't want to fight them, and I fought all of them. So right now ... I can do whatever I want."

This was Alvarez's first fight against a fellow Mexican since he defeated Julio Cesar Chavez Jr., in May 2017, and his seventh headline bout on Cinco de Mayo Weekend. Canelo has won four consecutive fights since he moved up to 175 pounds for a decision loss to Dmitry Bivol in May 2022.