Long before he became the no.7-ranked lightweight in the UFC (and a TUF winner to boot), Nate Diaz was throwing down in gyms and unregulated MMA events all over California.
In this rare video, a 17 year old Diaz can be seen in what is likely his first ever organized fight. Given that it's being held in a martial arts gym of some kind, it might have been a challenge match between two rival schools.
Diaz's opponent is representing Kihon, a martial arts gym located in Desert Hot Springs, California, while Diaz himself comes from a Gracie Jiu-Jitsu background. Similar to Pancrase rules, it appears that close-fisted strikes were not allowed in this fight, although palm strikes and submissions were.
This fight would have taken place roughly four years before his professional debut in 2004, when he defeated Alejandro Garcia with a triangle choke at WEC 12.