At a squat 5’7”, Shawn Porter will almost always be at a height disadvantage in the welterweight division. (photo by Ryan Hafey)

Given where he spent the bulk of his rich amateur background, opponents have quickly learn the hard way that he’s by no means the smaller man in the ring.

Though currently serving as a two-time welterweight titlist took nearly two years to work his way down to the division, as he was closer to the super middleweight division upon turning pro in 2008. The 165.5 pounds he weighed for his pro debut was in line with his fighting weight as an amateur, racking up an impressive 276-14 record as a middleweight and coming up two wins short of joining the 2008 U.S. Olympic boxing team.

“I think fighting 165 pounds is no secret that the majority of the guys that I fought as an amateur were a lot bigger than Errol Spence,” Porter (30-2-1, 17KOs) noted of his upcoming welterweight titlist unification clash  with the unbeaten Spence (25-0, 21KOs), who boasts a 2½” height and 3” reach advantage. “Not just bigger than Errol, they were a lot bigger than Errol Spence.

“I'm talking about guys like (former middleweight titlist) Daniel Jacobs, who fights at 160 pounds, 168 pounds now. I fought against Oleksandr Usyk, who is unified champion over there in the Ukraine, a heavyweight now. I fought him at 165 pounds back in the day when we were about 20 years old and beat him. I have wins against Jacobs and (unbeaten two-divisoin titlist) Demetrius Andrade.  The experience is there. The experience against taller, bigger opponents is there.”

Porter’s pro run isn’t any shorter on a who’s who of boxing personalities.

The 31-year old from Akron, Ohio—who now lives and trains in Las Vegas—will meet his ninth former or current major titlist in Spence when the two collide atop a Sept. 28 Fox Sports Pay-Per-View live from Staples Center in Los Angeles, Calif. He boasts a 6-2-1 record against the current batch, having fought to a draw with and a win over Julio Diaz in their two-fight set.

An Aug. 2014 loss to Kell Brook ended Porter’s first title reign, which lasted just eight months and boasting a single successful title defense. He enters this bout having just celebrated his one-year anniversary as a two-time titlist following a 12-round win over Danny Garcia last September. His lone successful defense of this reign came this past March, edging out the scrappy and taller Yordenis Ugas in taking a narrow decision.

Spence enters his second straight PPV headliner, on the heels of a 12-round shutout over Mikey Garcia this past March, one week after Porter’s aforementioned win over Ugas. The pairing of unbeaten pound-for-pound entrants ceased being competitive shortly after the opening bell, with Garcia—a now former four-division titlist who moved up from lightweight to take on the challenge—outgunned and ultimately fighting to survive.

The lone in-ring test of Spence’s career came in his title winning effort, stopping Brook in the 11th round of their May 2107 clash in front of a hostile crowd in Sheffield, England. That he’s otherwise blown past everyone put in front of him is a testament to his current standing as one of the sport’s elite talents, which is acknowledged by his upcoming opponent—although with the suggestion of their being more to the story.

“For me looking at Errol Spence, I don't look at him like he's a bigger guy than me,” insists Porter. “I don't think he's one of the bigger guys in the division. I think that he's been matched up against guys who have made him look a lot more powerful and bigger and stronger than he is.

“Trust me when I say he's met his match in this one.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox