Derrick Lewis Says He's Fighting Stipe After He Beats Junior Dos Santos

Junior Dos Santos is a BAD man, and Derrick Lewis knows beatin' him ain't gonna be easy, but when he does ... "The Black Beast" knows who's next in line for an ass-whoopin' -- Stipe Miocic.

Lewis is headlining UFC Fight Night 146 this weekend in Kansas against Dos Santos -- a 6'4", 250-pound ex-UFC heavyweight champion -- who's beaten 5 former UFC heavyweight champs.

The champs JDS has beaten ... Fabricio Werdum, Cain Velasquez, Frank Mir, Shane Carwin, and Stipe Miocic.

So, it's gonna be a TOUGH fight ... but Derrick tells TMZ Sports after he takes care of biz Saturday ... he knows exactly who's on deck for a date in the Octagon.

"Stipe is the next guy."

The fight ain't a pipe dream either ... Lewis told us Dana White actually tried to make the fight back in January -- but Derrick wanted to chill after fighting Daniel Cormier.

But, Stipe ain't the only guy on Lewis' hit list ... "The Black Beast" says he also wants to run back the Francis Ngannou fight.

"I have to get that fight out of the way again before I retire, ya know? Just to make it right for the fans. Not right for myself. Right for the fans."

Remember, Lewis won the July 2018 match ... but there were only 31 total strikes landed combined and it's widely considered one of the most boring fights ever in the UFC.

Lewis wants to rewrite history ... under one condition.