Tommy Fury says it's a wrap for Jake Paul's boxing career -- telling TMZ Sports he's going to knock the YouTuber-turned-fighter into retirement when they face off in the ring.
Fury -- lil' bro of boxing champ Tyson Fury -- finally agreed to be Paul's next opponent last week ... after initially saying the offer wasn't worth getting out of bed for.
We caught up with the 22-year-old earlier this week at LAX and had to ask what made him change his mind .