It has taken Oscar Collazo almost no time at all to climb to a rare boxing stratum, where he is fighting not so much against an opponent across the ring as he is competing against his previous best performances.

On Saturday in Cancun, Mexico, Collazo – a unified strawweight titleholder – may have penned his finest masterwork to date, systematically breaking down Edwin Cano for a fifth-round knockout victory.

The decisive punch appeared to come on a Collazo right hook to the body, crumbling the tough and game – but ultimately overmatched – Cano in the co-main event supporting the William Zepeda-Tevin Farmer II headliner.

Collazo, 12-0 (9 KOs), of Villalba, Puerto Rico, continued his romp through the 105lbs division by taking on Cano, 13-3-1 (4 KOs), of Queretaro, Mexico, in his home country in a meeting of southpaws and what was sold as another chapter in boxing’s storied Puerto Rico-versus-Mexico rivalry.

But it was clear from the outset that whatever grand conflict organizers or observers had in mind would actually be a one-way Autobahn that belonged exclusively to the 28-year-old Collazo.

He landed a couple of trademark right hooks in Round 1 – the second of which drew an audible gasp from the Cancun crowd – that weren’t enough to initially faze Cano, who responded by dutifully targeting Collazo’s body and trading with his opponent whenever possible.

Easier said than done. Collazo bobbed and weaved around a Cano right hook and probing jab late in the second round before splashing a right hook of his own upstairs on Cano.

In the third, Cano came out of the gate with a nifty counter hook, but it was one of his last moments of satisfaction. Time for Collazo to cook. He unleashed hooks, left crosses and uppercuts, leading with everything and making nothing predictable. Collazo would bust up Cano’s body, then return to the head when Cano dropped his elbows to protect his increasingly tender midsection. Toward the end of the round, Collazo tossed in, almost as an afterthought, a missile of a straight left hand that yanked Cano’s head violently.

Summoning more streams of punches in the fourth, Collazo hammered the body and hooked the chin, creating space when Cano closed the gap but tracking him down when he dared to consider stepping out of range for a moment’s respite. Cano wasn’t quite ready to go away, firing off his own combination that brought out a roar from the crowd.

By the fifth round, however, Cano was all but spent. Collazo poured on more leather, calculating in his punch selection, clinical in his precision and absolutely relentless in his delivery of punishment. With no defenses left, a shelled-up Cano absorbed a right hook that Collazo was able to compute and launch like a NASA engineer in the middle of the ring. Cano staggered away, dropped to a knee and slumped between the ropes, spitting out his gum shield and rolling to the canvas in agony.

The time of stoppage was recorded at 1 minute, 12 seconds of the fifth.

The come-forward Collazo no doubt wants one of the other strawweight titleholders – Melvin Jerusalem or Pedro Taduran – next. Might he eventually seek bigger fights by moving up the divisional ladder? At the moment, unified flyweight titlist Kenshiro Taraji is perhaps the only rational opponent worth moving up for, as the 5-foot-2 Collazo would be stretching himself to challenge any of the constellation of stars at junior bantamweight. We may have to continue measuring him against himself for now.

Jason Langendorf is the former Boxing Editor of ESPN.com, was a contributor to Ringside Seat and the Queensberry Rules, and has written about boxing for Vice, The Guardian, Chicago Sun-Times and other publications. A member of the Boxing Writers Association of America, he can be found at LinkedIn and followed on X and Bluesky.