LAS VEGAS – Michel Rivera believes Jose Matias Romero did enough to upset Isaac Cruz in Matias Romero’s most recent fight.

None of the three judges agreed with how Rivera saw their 12-round lightweight match March 13, but Rivera was impressed with how Matias Romero made their fight difficult for the heavily favored Cruz (21-1-1, 15 KOs). Matias Romero took that fight on barely one month’s notice, which made his performance against Mexico’s Cruz more impressive to Rivera.

“I believe he won the fight, but he didn’t get the decision,” Rivera told BoxingScene.com. “The fight was close, but to me, he won. It was good that he finished the fight. People thought that Cruz would knock him out in the first round or within five rounds. That didn’t happen because the guy is tough and he’s in condition. He won the fight, to me.”

Judge Steve Weisfeld (118-109) credited Cruz for an easy victory, though judges Kevin Morgan (115-112) and Glenn Feldman (114-113) had it much closer in a fight Showtime televised from Mohegan Sun Arena in Uncasville, Connecticut. Regardless, Rivera recognizes that Argentina’s Matias Romero is capable of testing him in their 10-round junior welterweight fight Saturday night at Mandalay Bay Resort and Casino’s Michelob ULTRA Arena.

“I’m familiar with him,” Rivera said. “He has a great record, 24-1, and he lost with a good guy in his last fight. And I know that he’s a guy that has good technique. He’s a good fighter.”

Until approximately a month ago, Rivera’s head trainer, Herman Caicedo, assisted Matias Romero’s father and head trainer, Ruben, in preparing him. Caicedo worked Matias Romero’s corner for the Cruz fight and expected to man his corner again for his subsequent bout.

Once the Rivera-Matias Romero match was made as the opener of Showtime’s tripleheader (10 p.m. EDT; 7 p.m. PDT), Caicedo allowed Matias Romero to continue training at Caicedo’s gym in Miami, just at different times than the Dominican Republic’s Rivera.

Matias Romero (24-1, 8 KOs) and Rivera (21-0, 14 KOs) did not spar against each other while preparing for their previous bouts. Three-and-a-half months after Matias Romero tested Cruz, Rivera recovered from a flash knockdown during the sixth round to knock out Jon Fernandez in the eighth round of their July 3 bout at Dignity Health Sports Park in Carson, California.

Rivera led Spain’s Fernandez (21-2, 18 KOs) by the same score, 67-65, on all three cards entering the eighth round of a 12-round WBA elimination match.

“It was a good fight,” Rivera said. “I still think it wasn’t a knockdown. OK, it was a knockdown because my gloves hit the floor. But I didn’t get hit. I lost balance and I went down. But he was believing I was hurt. … I learned from the mistake I made when I went down. I didn’t lose my composure. I stayed relaxed and finished that round off, didn’t panic. It’s already a lost round, a 10-8 round. But I relaxed, came back the next round and won the round. One important point is they were thinking the big puncher was Fernandez, but I showed that I have big power, too.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.