To unify the IBF, WBA, WBC and the Ring 126 pound titles. Don't think Sanchez ever fought someone with the speed, power and boxing ability of Gamboa in his prime.
Tough fight but I think Sanchez had enough dimensions to his game to win. He always fought his best against the best competition, and I think he would rise to the occasion. But it would be a fun and competitive fight.
Have you ever heard the Sun Kil Moon song about him? Well actually despite the title only the first verse is about him, but the lyrics are all about boxers who passed too soon. Hauntingly beautiful.
Sanchez tended to start slowly and then come on in the second half. So, Gamboa probably has some good moments early before Chava grinds him down, before lowering the boom in the later rounds.