Francis Ngannou Says Tyson Fury Will Regret Underestimating Him In Boxing Match

Francis Ngannou says Tyson Fury will rue the day he underestimates the former UFC heavyweight champ!

"[Tyson] has said a lot of things. He better just get ready for October 28th because if he's not taking this seriously, I think he might get surprised and get some regrets for his life," 36-year-old Ngannou told TMZ Sports just days after his highly anticipated boxing match with the Gypsy King was announced.

Fury, by nearly everyone's account, is the best present-day heavyweight boxer ... but Ngannou isn't content with cashing a big check just to lose his boxing debut.

"I'm going there to box. I'm going to walk into this fight as a boxer. And I'm impressed to see how people are counting me out of this and it also gets me excited. You know, one more thing that they keep doubting on me. And as usual, I might keep proving them wrong."

Despite Francis' confidence, Tyson doesn't seem too concerned, sending a message to Ngannou over social media, taking a shot at his opponent.

"Ngannou, you're getting it, you big dosser. You big stiff dosser, you're getting knocked out. You're getting knocked out, friend!"

We also talked to the former UFC star about how he plans to prepare for the bout ... and Francis is thinking about bringing in two of the greatest heavyweights of all time.

"I think getting some advice or some training from Mike Tyson would be good. I also think of somebody like Lennox Lewis, which could be good."

Francis continued ... "I love his boxing style, very basic, but very sharp, efficient, you know, want to all those stuff like classic, but very good, I love stuff like that. So yes, one of those guys, we are reaching definitely reaching out."

FYI, Fury is a heavy favorite -- to the tune of -1250 (risk $1,250 to win $100) -- but Ngannou is unbothered.