McWilliams Arroyo had the full training camp. He had all the preparation. And in less than five rounds, he became the WBC's interim flyweight champion of the world in the Canelo Alvarez-Avni Yildirim co-main event at Hard Rock Stadium in Miami on Saturday.

It became clear early on that Arroyo also had the realistic edge against Abraham Rodriguez, a late replacement who arrived in Miami on Friday.

And by the fourth round, it showed. Arroyo (21-4, 16 KOs) pummeled Rodriguez (27-3, 13 KOs), from Tijuana, Mexico, throughout the round, eventually forcing him to one knee and knocking him down. The onslaught continued in the fifth round, although Rodriguez held up well considering the lack of time to properly train. It led to Rodriguez' corner waiving the white towel midway through the fifth round to stop the one-sided fight.

Arroyo, from Fajardo, Puerto Rico, was dominant throughout a fight that was supposed to be against Julio Cesar Martinez.

Martinez had to withdraw from the bout on Thursday with a small right hand fracture suffered during a sparring session. He had hoped to continue to train, but the injury got worse earlier this week.

After Arroyo's powerful victory, perhaps he'll be able to fight Martinez later this year.

It was Rodriguez' first loss since 2018 against Angel Acosta, also the last time he fought in the United States. That fight was for the WBO junior flyweight title. This time around, for another belt, was a similar result.

This fight represented Arroyo's fourth straight win.

Forrest salvages a majority draw against Zhang

Jerry Forrest went down once. Twice. Three times in three rounds. And yet, the heavyweight kept getting up. Kept enduring Zhilei Zhang's early onslaught and power. Kept coming at Zhang -- and eventually Forrest fought his way back to a tie that felt like a win.

Forrest and Zhang ended in a majority draw, with judges Rocky Young and Fernando Barbosa scoring the fight 93-93 and Rose Lacend giving the fight to Forrest, 95-93. After the bout, Forrest celebrated like he won and -- even before the scores were announced -- did a backflip in the ring.

Zhang, who looked like he was going to coast to an easy win with a big advantage in the first three rounds, held on to his undefeated record. Barely.

What looked like an explosive fight early on turned into a hugfest by the middle rounds, with both Zhang (22-0-1, 17 KOs) and Forrest (26-4-1, 20 KOs), looking fairly exhausted by the middle of the sixth. That continued into the seventh, when Forrest landed 26 punches as compared to nine for Zhang, according to CompuBox.

Forrest, of Newport News, Virginia, rallied after a rough first couple of rounds, in which he was knocked down three times. Zhang, of Zhoukou, China, was cut by a head-butt in the eighth.

Despite the big punches absorbed by Forrest and the early knockdowns, Forrest appeared to be the more active and conditioned fighter late.

Forrest also was aided by a point deducted from Zhang in the ninth round for holding Forrest's neck. That point ended up being a major difference in the fight, and was seemingly a result of what appeared to be exhaustion for Zhang over the last four rounds.

Pacheco dominates Gomez in unanimous decision

Diego Pacheco might have wanted the knockout. The 19-year-old had to settle for a unanimous decision win over veteran Rodolfo Gomez Jr. by a closer-than-expected 79-73 margin on the judges' scorecards in a super middleweight fight.

Pacheco (11-0, 8 KO), of Los Angeles, landed some good punches, including a couple of nice uppercuts throughout the fight, but this was only the third time he went the distance and only the second time in his career he went beyond the fourth round.

Gomez (14-5-1, 10 KO), of Laredo, Texas, was a good test for Pacheco. Gomez connected on some big punches and seemed to frustrate Pacheco intermittently. It also was good round work for Pacheco in his first full eight-round fight. Gomez gave Pacheco enough to now look back at as he prepares for his next fight.

It was Gomez's first defeat since Sept. 24, 2016, when he lost to Roberto Ramirez Uriarte by unanimous decision.

Castro demolishes Moraga in two rounds

Marc Castro needed one punch, eight seconds and a left jab. That's all it took for the junior lightweight prospect to knock down UFC veteran John Moraga in the first round. From there, it was a matter of time for Castro, the highly touted amateur fighter in his second pro fight.

Castro (2-0, 2 KOs), of Fresno, California, knocked down Moraga (1-3, 1 KO) three times in two rounds to register the knockout, finishing the fight with a left uppercut.

Moraga, of Phoenix, has had an impressive MMA career, with a 19-7 record and a UFC flyweight title shot in 2013 that he lost to Demetrious Johnson. His first knockout loss in boxing was Moraga's third defeat in four pro bouts.

The 21-year-old Castro is still very, very early in his pro career, but the friend of star fighter Ryan Garcia made easy work of an overmatched opponent.