LAS VEGAS — The time has come for boxing’s biggest superstar to take on his next daunting challenge.

Canelo Alvarez will attempt to become a four-division world titleholder when he takes on WBO light heavyweight world champ Sergey Kovalev. Alvarez will be making a 15-pound jump from middleweight to light heavyweight for this fight.

But before Alvarez and Kovalev square off in the main event, there are several undercard bouts with key implications, including ESPN’s 2017 prospect of the year Ryan Garcia vs. Romero Duno in a 12-round lightweight fight. The pro debut of Evan Holyfield, son of former cruiserweight and heavyweight champion Evander Holyfield, lasted all of 16 seconds before Holyfield scored the knockout.

Here’s how the fights are going down at the MGM Grand Garden Arena.

Blair Cobbs vs. Carlos Ortiz, 10 rounds, welterweights

Fight in progress …

Holyfield smokes Winstead

Junior middleweight Evan Holyfield (1-0, 1 KO) needed only 16 seconds to win his pro debut in a knockout of Nick Winstead (0-2).

Holyfield, whose legendary father — four-time heavyweight world titleholder Evander Holyfield — was ringside, stormed out of his corner and went right at Winstead. Holyfield landed a flurry of punches, including a hard left hook that rocked Winstead. Holyfield landed multiple shots and kept pressing forward until Winstead went down and referee Robert Hoyle stopped the fight as Winstead, 21, of Abita Springs, Louisiana, was getting to his feet. The crowd booed the stoppage with vigor.

“It was such a blessing to be able to showcase my talent on the card like this,” Evan Holyfield said. “I was just expecting to box and I just went out there and did my job. I was zoned in and God just had me.”

Holyfield, 22, of Atlanta, turned pro guided by Main Events, the same promoter that signed his father out of the 1984 Olympics and developed the elder Holyfield into a superstar and the undisputed cruiserweight and heavyweight champion.

Evan Holyfield also has conditioning coach Tim Hallmark, who worked with Evander for many years, on his team.

Murtazaliev wins title eliminator

Junior middleweight Bakhram Murtazaliev rolled to a unanimous decision over Jorge Fortea in a world title elimination fight.

Russia’s Murtazaliev (17-0, 13 KOs) won by scores of 120-108, 119-109 and 118-110 to secure mandatory challenger status for unified titleholder Julian “J Rock” Williams.

“I feel very good. I was listening to the coach. I didn’t try to force anything and I was just listening to my coach,” Murtazaliev said. “I’ll get better and better and better.”

Murtazaliev, 26, who fights out of Oxnard, California, was the bigger man and more aggressive throughout the bout — allowing him to keep Fortea (20-2-1, 6 KOs), 28, of Spain, at bay. Fortea, whose seven-fight winning streak ended with this loss, had a hard time getting inside, although he did land some good shots, as evidenced by both fighters’ faces being marked up by the end.

Kalkreuth outpoints Smith

Cruiserweight Tristan Kalkreuth (3-0, 2 KOs), a 17-year-old from Duncanville, Texas, whom Golden Boy signed in June, outpointed tough Twon Smith (3-4, 2 KOs), of Oklahoma City. Kalkreuth, a junior in high school, won 40-36, 40-36 and 39-37, but Smith never stopped going at him in a spirited effort.

But Kalkreuth, who stood up to some clean shots, landed many more punches en route to the clear win. Smith, 32, lost his fourth fight in a row, but the previous three were each by six-round decision.

“I knew he was tough. He had twice the pro experience I did,” Kalkreuth said. “He’s pretty much a veteran, but for that being my third fight I think I did good. I wish I put more punches on him and obviously the one thing that boxers want is to get the KO and that didn’t happen, but I know this fight is going to help me later down the road.”

Nursultanov shuts out Olivas

Middleweight Meiirim Nursultanov (13-0, 8 KOs), 26, a Kazakhstan native based in Oxnard, California, won a vacant regional belt as he routed Cristian Olivas (16-6, 13 KOs), 27, of Mexico. Nursultanov won by shutout, 100-90 on all three scorecards, as he handed Olivas his fourth loss in a row — all by decision.

Nursultanov did as he pleased throughout the fight, driving Olivas back with a variety of punches and rarely getting hit with anything in return.

“I was very surprised at how durable he was, but it was a good experience,” Nursultanov said. “He was very tough. I needed this to get rounds of experience.”

Melikuziev stops Collard with body shots

Light heavyweight Bektemir Melikuziev (3-0, 3 KOs), who turned pro in June, used a powerful body attack to stop Clay Collard (4-2-3, 1 KO), 26, of Las Vegas, in the fourth round of their scheduled eight-rounder.

In that fourth round, the Indio, California-based Melikuziev, 23, of Uzbekistan, who is trained by Joel Diaz, dropped Collard twice with body shots. After the second knockdown referee Robert Hoyle stopped the fight at 2 minutes, 22 seconds.

Still to come:

  • Ryan Garcia vs. Romero Duno, 12 rounds, lightweights

  • Title fight: Seniesa Estrada vs. Marlen Esparza, 10 rounds, for vacant WBA interim women’s flyweight title