35-year-old Poirier joined Babcock on the "TMZ Sports" TV show (airs weekdays on FS1) -- about a week before his UFC 302 main event title fight against champion and current pound-for-pound king, Islam Makhachev. We asked Dustin how important it was for him to be crowned champ.

"It's greatly important," Dustin said.

"I think I've said this over and over again. I've done everything in the sport except wear the undisputed crown. That's the last thing I have left to do. I think that puts a stamp on a Hall of Fame career that really, to me, it locks me in there with the greats."

FYI, Poirier was interim lightweight champ in 2019 after defeating Max Holloway ... but lost to Khabib Nurmagomedov later the same year when they met in the Octagon for a unification bout.

In 2021, DP had another crack at the belt ... but lost to Charles Oliveira.

Will the third time be the charm for Poirier? Many, including Islam, believe the matchup is a bad one for Dustin.

In fact, Makhachev previously told us "[Dustin's] problem is his style. That's one problem the guy has. His weak point is wrestling and grappling."

So, we asked Dustin about Islam's scouting report.

"I don't know if it's a weak point, but he's right," Poirier admitted, before making it abundantly clear he isn't looking to win a grappling match.

"People who try to slow the fight down and make it a grappling chess match, those have been the hardest fights for me to get going because I do best when it stays a fight, when it doesn't slow down, when it's a scramble with punches flying and both of us bleeding. That's where I do the best work."

"And I'm not trying to hold him down and win rounds. I'm trying to knock him out and hurt him and finish him and get out of there. That's the way I fight."

We also talked to Dustin about his charitable work. As usual, Poirier is auctioning off his entire fight kit ... but he's doing so much more with his The Good Fight organization.