Chandler made his spectacular UFC debut at UFC 257 on Saturday night -- obliterating the #6 ranked lightweight Dan Hooker in an explosive 1st round knockout.

After the fight, Dustin Poirier -- who beat Conor McGregor that night -- shot down a possible scrap with Chandler.

"I can guarantee I won’t be fighting Michael Chandler,” Poirier said after the fight ... suggesting Chandler simply hasn't earned the right to share the octagon with him.

No disrespect to [Chandler]. He seems like a good husband, a good father, he speaks well, has a lot of respect, carries himself very well. It’s not a knock against him. It’s just my feelings toward the division and the sport."

FYI, Chandler has only fought 1 time in the UFC -- but he's had 26 pro fights in other MMA promotions including Bellator where he won 18 of 23 fights and became the Bellator lightweight champ.

So, how does Chandler feel about the situation? Confident.

Chandler says it's Dana White who ultimately calls the shots -- not Poirier -- and he knows Dana respects his resume.

In fact, Chandler says he believes UFC will make the fight -- and he can't wait.

"Chances are we're gonna throw down and chances are I'm gonna have the gold around my waist by the end of the year," Chandler tells TMZ Sports.

"He's gonna be very very surprised by my power and I think I'll finish him in the first 2 rounds."

There's more ... we also spoke with Chandler about luring Khabib Nurmagomedov out of retirement for a 30th fight -- and yeah, he wants a piece of the Eagle!

"If you ever do wanna come back ... try to beat me, but you're gonna end up 29 and Chandler!"

He also ripped Khabib for tweeting about Conor McGregor after Conor's loss -- saying, "It is disheartening, a little bit immature for [Khabib] to be chirping from the sidelines."