Jake Paul says he's 100,000% positive his bro, Logan Paul, would wreck CM Punk in a real UFC fight -- and now he's firing back at Dana White, who's been trashing the idea all over town.
"Dana White's thinking small," Jake told us outside Craig's with his GF, Erika Costell.
Remember, after Logan fought KSI in a wildly successful pay-per-view fight on YouTube in August ... the social media star told us his goal is to fight in the UFC Octagon -- and he's dead serious.