LAS VEGAS – Frank Martin was certain while preparing to box Michel Rivera on Saturday night that he had already beaten a better Dominican lightweight contender this year.

Jackson Marinez already had two losses on his record when Martin stopped him in the 10th round July 9 at Alamodome in San Antonio. Marinez’s first defeat was a very controversial 12-round unanimous decision to Rolly Romero, though, and Martin reminded reporters after he dropped and out-pointed Rivera that records aren’t always accurate comparative tools when you assess opponents.

Martin (17-0, 12 KOs) knocked Marinez to the canvas once in the ninth round and again in the 10th round. The Detroit native led Marinez (20-3, 8 KOs) by scores of 88-82, 88-82 and 87-83 when their scheduled 10-rounder was stopped immediately after that second knockdown during the 10th round.

Marinez managed to land his fair share of punches on Martin, however, which made Martin work on tightening his defense during training camp for the Rivera fight.

“I knew that from the jump Marinez would be the better fighter,” Martin told a group of reporters after he defeated Rivera. “It was just people look at undefeated records. You know, it’s fighters with losses that’s better than a lotta guys that’s undefeated. You know, styles make fights. You know what I mean? We knew that Marinez was a better like fighter than [Rivera], just more experienced and stuff. We knew the guy I fought tonight would have more finesse and stuff, but Marinez was the more experienced and, you know, game fighter.”

The 27-year-old Martin, who was raised in Fort Wayne, Indiana, dropped Rivera in the seventh round, but their 12-rounder went the distance at The Chelsea inside The Cosmopolitan of Las Vegas. Judges Tim Cheatham (120-107), Dave Moretti (117-110) and Steve Weisfeld (118-109) scored Martin a wide winner of their WBA elimination match.

Martin mostly befuddled Rivera (24-1, 14 KOs) with his athleticism, defense, footwork, intelligence and speed throughout their “Showtime Championship Boxing” main event.

The skilled, strong southpaw emphasized afterward that having a full training camp to prepare for Rivera also led to a more complete performance than when he beat Marinez. Martin was supposed to oppose Panama’s Ricardo Nunez on July 9, but Marinez replaced him on eight days’ notice because Nunez (23-4, 21 KOs) couldn’t obtain a visa to enter the United States.

“I knew that the fight with Marinez was gonna be a tougher fight than this fight,” Martin said. “I can’t really stand on that because I didn’t have time to train for him. I had time to train for Rivera.”

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