"Man, I want to be one of the best," Moreno told TMZ Sports this week ... "I want to be of the history of the flyweight division. I won the title twice in the past, but I feel I have to do a little bit more, you know?"

Of course, G.O.A.T. is a subjective debate with no definitive answer. Still, most agree Demetrious Johnson is the best ever in the division, with Henry Cejudo making a strong case for himself (Triple C beat Mighty Mouse -- not to mention he won an Olympic gold medal and became UFC bantamweight champion, too).

Moreno, 30, a 2x champ who twice defeated Deiveson Figueiredo, is in the midst of a rare losing streak ... albeit to some of the best fights in the world.

Brandon lost his last two contests by split decision ... losing his belt to Alexandre Pantoja at UFC 290, and then taking an L at the hands of Brandon Royval at UFC Fight Night in February.

Now, Moreno, the number 2 ranked contender, is set to step back in the Octagon against number 3 ranked Amir Albazi, a 17-1 MMA star who hasn't lost since he entered the UFC in 2020 (he's 5-0, and 17-1 overall as a pro).

Brandon understands he's a dangerous and motivated fighter ... and he's got his hands full.

"[Albazi's] an amazing fighter. He's a very good fighter, very talented, very motivated, I mean I know he understands if he beats me, he's gonna be in the conversation for the title next, you know?"

Pantoja, the champ, already has a bout scheduled, but the winner of Brandon vs. Amir would likely get the next crack, and Moreno's hyped!

"The goal is there to be the champion again. And, the final goal is to grow my legacy even more. I think I have more to do with this sport. I have a lot of hunger to succeed. And I mean, it's an interesting fight because I think this is going to be another highlight of my career."