Frank Martin's hoping more people keep doubting him ahead of his fight against Gervonta "Tank" Davis ... telling TMZ Sports he uses the criticism as "fuel" -- and can't wait to shock the world!!
The WBA Lightweight World Title fight is slated for June 15 at the MGM Grand in Las Vegas ... and Martin (18-0 w/ 12 KOs) says he feels confident to get in the ring with one of the best pound-for-pound boxers in the world.
"I got a lot of things that him, the world, a lot of people may not expect that I got," Martin told us this week.
While some people are skeptical of his chances, Martin isn't losing any sleep over it.
"That s*** embraced," Martin said, "Bet with me, win with me. That s*** is one of them things I embrace. I'm eating off it. It's fuel to me, so it is what it is."
"It ain't gon' change. I just gotta go out there and do the unexpected."
Just because Martin is not the betting favorite (Davis' around -600) in this fight doesn't mean he expects Tank to be relaxed in the ring ... he actually believes the "balanced" and "well-rounded" fighter will be on his A-game.
That's what he's hoping for -- and he sends a direct message to Tank.
"I hope I get the best version of you 'cause you gon' get the best version of me, for sure."