MANILA, Philippines – If betting odds are made on flyweight fights, then Brian Viloria is a bookie’s worst nightmare.

The 34-year-old Viloria has had a career most fighters would dream of, winning major titles at 108 and 112 pounds and outlasting all of his higher profile teammates on the 2000 US Olympic team. He became the first fighter to unify two flyweight titles since 1965 when he knocked out Hernan Marquez in one of the best fights of 2012.

But ‘The Brian Viloria Story’ cannot be told without mentioning the dark times. The three-fight stretch in 2006-’07, when he was out-hustled in two fights with Omar Nino and Edgar Sosa and was held to a draw in a fight later ruled a no-decision against the former.

The night he was rushed to a Manila hospital after being stopped in round 12 against Carlos Tamara in 2010, or when his championship gold slipped through his fingers at the hands of a hungrier Juan Estrada in 2013.

Long-time Viloria assistant Ruben Gomez told this writer in 2011 that Viloria “should have never lost” to anyone he had faced. Like many top athletes, Viloria’s greatest enemy has often been himself.

Those shortcomings are the reason Viloria is a solid underdog heading into Saturday’s fight with Roman Gonzalez at Madison Square Garden, which will be the co-featured bout to the Gennady Golovkin-David Lemieux middleweight title unification bout on HBO Pay-Per-View.

Despite the fascination with Golovkin, whom many feel can fill the star void left by Floyd Mayweather Jr.’s retirement, Gonzalez has garnered much curiosity himself. The 28-year-old from Managua, Nicaragua assumed Mayweather’s spot atop THE RING’s pound-for-pound ratings after Mayweather hung up his gloves.

Gonzalez, a champion of three divisions, has been perfect in his career and perfection is easy to trust. Viloria has been anything but perfect but he feels his losses have built up character in him that no amount of training otherwise could.

“It toughened my skin a whole lot,” Viloria (36-4, 22 knockouts) told RingTV in a phone interview. “It made me the resilient person who I am today. It made me not blink in the eye of challenges. It hardened me a lot, going through those experiences. It just seems that nothing fazes me.”

At several times in his career, Viloria has been dismissed as an inconsistent underachiever who would never live up to his potential. Those have been the times when he was most dangerous.

Like in 2009, when he knocked out Ulises Solis, then the top junior flyweight in the world, with one right hand to win the IBF title. Or when he faced pound-for-pound-rated Giovani Segura – who was fresh off two knockout wins over Ivan Calderon – and battered him relentlessly until the fight had to be stopped.

“I have relished that role of being the underdog,” said Viloria. “It just lights a fire under my ass to get me to train extra hard, gets me extra motivated to do well in the fight. Come Saturday night, I think everybody is going to see one of the big upsets of the year.”

Due in part to the up-and-down nature of Viloria’s career, he has yet to crack the pound-for-pound ratings. It’s hard to overstate what this win would do for validating his legacy as one of the most accomplished fighters of his time but he’s not dwelling on that yet.

“I know what it means; I try not to let it be too big to think about right now,” said Viloria.

He knows that heavy is the head that wears the crown, particularly when the lights are brightest.

“I think all the pressure is on [Gonzalez],” said Viloria, who was born in Waipahu, Hawaii, but raised for five years by his grandparents in Narvacan, Ilocos Sur, Philippines.

“He has to perform like the No. 1 pound-for-pound fighter. That puts a lot of pressure on him. I’m just going in there as myself to perform the best I can and leave it all in the ring. He has a lot to lose; I have the whole world to gain if I do my best and beat him in the ring.”

Away from wins and losses, Viloria’s style passes the eye test. When he’s dedicated himself fully to training, he is a versatile boxer-puncher with a disciplined body attack, a sneaky counter hook and one-punch power in his right hand.

Gonzalez, who once collected trash with his father to make ends meet, didn’t get to where he is by accident.

But Viloria knows that once the bell rings, it doesn’t matter what mythical designation you’ve been bestowed by the press or what the betting odds were for the fight.

“When everyone keeps putting that up about him being No. 1 pound-for-pound and being the best. At the end of the day, he’s still a human being with two hands like me,” said Viloria.

“I kind of like having that doubt in front of me, knowing that I have to prove somebody wrong. In this case, I have to prove the whole world wrong.”

Ryan Songalia is the sports editor of Rappler, a member of the Boxing Writers Association of America (BWAA) and a contributor to THE RING magazine. He can be reached at [email protected]. Follow him on Twitter @RyanSongalia.