Looks like Fujimoto is Dubois's best opponent, as he's ranked #15. Don't like these guys ranked so highly and not have fought anyone. Here's another one for you. Romanov has never fought outside of Russia, and nobody even remotely close to top 15. And he's ranked WBO #8.
https://boxrec.com/en/proboxer/768670
https://boxrec.com/en/proboxer/768670