Boxing question: Mexico vs Puerto Rico, who helped who first in hiring opposite country trainers? See Below!!!?

Ok, I know the title isn't helpful, therefore this is the COMPLETE Question. I want to which boxer (from Mexico and Puerto Rico ONLY) was the first to hire a trainer from the opposite country? For example did a Mexican fighter first hire Puerto Rican trainer/manager? When? Or was it a Puerto Rican fighter who first hired a Mexican trainer/manager? When? Most recently I read that Mexican trainer Robert Garcia was just hired by Puerto Rican boxer Thomas Dulorme. I see this as Ironic because of the great boxing rivalry between these two countries, and I would assume that neither of them would seek the help of one another. But as a Mexican I respect Puerto Rican boxing, boxers, and trainers, it's a great rivalry, and we both have great champions!!!! Thank You