UFC's Derrick Lewis Calls Out Greg Hardy, 'I Like KO'ing Wife Beaters'

If Greg Hardy fights his way into a UFC contract, one of the biggest stars in his division wants a piece of the ex-NFL star ... with Derrick Lewis saying, "I like knocking wife beaters out."

Hardy is reportedly getting his shot during the UFC Contender Series -- in which up-and-coming MMA fighters compete for a chance at a UFC contract. It's where UFC star Sean O'Malley got his start.

Hardy (who's 3-0 as an amateur) would obviously compete in the heavyweight division -- where Derrick "The Black Beast" Lewis is ranked #6 in the world.

So, how does Lewis feel about a potential showdown somewhere down the line?

"He's a wife beater ... I'd like to get in there with him."

Lewis is referring to Hardy's domestic violence case -- in which he was initially convicted of attacking his then-girlfriend. The conviction was later thrown out when the alleged victim stopped cooperating with prosecutors.

Still, Lewis ain't letting Hardy off the hook.

"I'll fight Greg Hardy ... It'll be like vice versa him beating on a woman. I'll be beating him like he was a woman."

Why so much animosity?

"I grew up watching my mom and my stepdad fight," Lewis says ... "Fistfighting every day for stupid stuff. I don't tolerate stuff like that at all."

First things first ... Lewis has a brawl with Francis Ngannou lined up at UFC 226 on July 7 ... about a month after Hardy gets his UFC shot.

Stay tuned ...