LAS VEGAS – The victory that vaulted Vincent Astrolabio into this position didn’t exactly make Nikolai Potapov take notice.

The Philippines’ Astrolabio upset former two-division champion Guillermo Rigondeaux by unanimous decision to earn a spot in a 12-round IBF bantamweight elimination match against Potapov on Saturday night. Astrolabio dropped the heavily favored Rigondeaux, a Cuban southpaw who was 41 when they fought, in the eighth round February 26 in Dubai and consequently barely won by the same score, 95-94, on all three scorecards.

Potapov promised that Astrolabio will encounter a much more energetic, hungrier opponent when they fight in the opener of Showtime’s three-bout broadcast from The Cosmopolitan of Las Vegas (10 p.m. ET; 7 p.m. PT).

“Astrolabio is a good fighter, a tough fighter,” Potapov told krikya360.com through a translator. “The fight versus Rigondeaux wasn’t very impressive to me because Rigondeaux looked completely finished. He didn’t have any desire to win the fight, but if not for the knockdown, the fight would’ve been a draw. But with that being said, I’m taking him very seriously and we’ve been training as if this was for the world title. I’m supremely prepared for this fight.”

Russia’s Potapov (23-2-1, 11 KOs) is ranked third by the IBF in its 118-pound ratings. Astrolabio (17-3, 12 KOs) is ranked sixth by the IBF.

The winner will become the IBF’s mandatory challenger for undefeated, undisputed bantamweight champ Naoya Inoue (24-0, 21 KOs). Japan’s Inoue could move up to the junior featherweight limit of 122 pounds for his next fight, which would leave the Potapov-Astrolabio winner to fight second-ranked Puerto Rican contender Emmanuel Rodriguez (21-2, 13 KOs, 1 NC), who lost the IBF belt to Inoue in May 2019, for an unclaimed championship.

Regardless, Potapov is thankful for another chance to position himself for a title shot after losing what was considered a controversial 12-round majority decision to Chicago’s Joshua Greer Jr. (then 20-1-1) in July 2019 at Prudential Center in Newark, New Jersey.

“I put the Greer fight behind me,” Potapov said. “One of the things that I know that I could’ve improved on was to be a little bit more active in the 11th and 12th rounds, which is what I would do in this fight. I feel that I won the fight [against Greer], but the lesson I learned was to win even more convincingly. That’s what the plan is for December 17th.”

The Potapov-Astrolabio bout will precede two more title eliminators Showtime will televise Saturday night.

Venezuela’s Jose Uzcategui (32-4, 27 KOs) and Russia’s Vladimir Shishkin (13-0, 8 KOs) are set to meet in the 12-round co-feature, an IBF super middleweight elimination match. Indianapolis’ Frank Martin (16-0, 12 KOs) and the Dominican Republic’s Michel Rivera (24-0, 14 KOs) are scheduled to fight in the 12-round main event, a WBA lightweight eliminator.

Keith Idec is a senior writer/columnist for krikya360.com. He can be reached on Twitter @Idecboxing.