You gotta watch this video ... UFC fighter Dominick Reyes passionately explaining why he's convinced he's the guy who will finally beat Jon Jones -- and he's FIRED UP!!!
"I got these hands. I got this heart. I'm Mexican. He's never fought a Mexican. I'm tough as s**t and I'm never gonna stop!"
Reyes is coming off a 1st-round highlight-reel knockout of ex-UFC champ Chris Weidman -- and he tells TMZ Sports he's sick of waiting for his crack at the G.O.A.T.
"I've taken out 6 guys in a row in my division.