15 rounds,very underrated fight between two boxer punchers. Jimenez might be a bit more complete,but Watanabe was very good at doing his own thing and perhaps..he had more talent. Who wins? By what?
Assuming the fight is at Super Fly, I'd take Watanabe. He was more proven at that weight and imo, just the better fighter.
Watanabe in my opinion is the best H2H Super Fly ever in his prime. Amazing, fluid offensive talent and movement. I pick him.