Jermall Charlo Says Canelo Fight Would Cement Legacy, If He Can Knock Him Out

Boxing star Jermall Charlo is an undefeated champion, but says if he wants to be remembered as an immortal fighter, he needs to fight and KNOCK OUT Canelo Alvarez.

The 30-year-old WBC middleweight champ (30-0, 22 KO's) is fighting Sergiy Derevyanchenko Saturday night on Showtime. Derevyanchenko -- a former amateur champ -- has only lost 2 pro bouts and gave Gennady Golovkin a tough fight.

Beating Sergiy would be a good win ... but Charlo tells TMZ Sports if he wants to be remembered as one of the greatest ever, he needs to go big game hunting.

Big ... as in the biggest star in the sport, 30-year-old Alvarez (53-1-2, 36 KO's).

"I just know [a Canelo fight is] always getting closer. One day I'm gonna get that call. That's all I can always dream for. Hope to fight the best. The best fight the best in the world."

Jermall says it's not enough to fight Canelo, or even just beat him ... he's gotta knock his ass out.

"I gotta fight him and once we fight, I knock him out and then everyone in the world will be able to cement my legacy as one of the best to ever do it."

Why is the KO necessary?

Charlo says Alvarez was already beaten by Floyd Mayweather back in the day, so he's gotta do what no other fighter has ... stop Canelo.

And, Jermall says he's ready ... it's just up to Canelo to accept the fight.