Of fighters not mentioned, I’d pick Carlos Ortiz. I think he had the smarts and the physical strength to outbox, outthink and cope with Chavez aggression.
In mexico there is always an argument about him and Salvador Sanchez. That said, IMO, Duran, Henry Armstrong , Sanchez , Taylor and Whitaker stood a chance.
Sanchez might be a little too small for him. We never saw how Sanchez might have filled up in the higher divisions.
Crawford stopped Spence who is far bigger than anybody Chavez beat, there`s no way Chavez could beat Crawford at welter, Bud has more reach and power than anybody Chavez beat.
Light weight /jr.welter version of Crawford. Chavez was well past prime at welter, many good fighters beat him at that weight. The post asked the question of who beats prime Chavez at light weight right?
While there's a few I'd pick to beat Chavez prime vs prime at lightweight, theirs no one I've seen who'd dominate him. and espcially no one beats the" dog **** out of him". That includes Ortiz, who based on my observation I doubt beat Chavez at all prime vs prime.