Jake Paul Guarantees Knockout Win Over Nate Diaz, '100%, He's Going To Sleep'

Jake Paul says he's a completely different fighter after experiencing the first loss of his boxing career ... and that could be bad news for Nate Diaz, 'cause The Problem Child tells TMZ Sports he's going to put his opponent on the canvas.

Jake and Nate are meeting in the ring for their highly anticipated fight in Dallas on August 5 ... and it's clear his defeat at the hands of Tommy Fury has him laser-focused on winning again.

"Man, I have the biggest chip on my shoulder, the biggest chip on both shoulders," Jake told Babcock on the "TMZ Sports" TV show. "Coming back with vengeance, refilled with that hunger that I had in the beginning of the sport to prove to people what I was capable of."

"The lion lost. I've retreated back into the jungle, I took notes of everything, I got better, I trained, and now this lion is going to come out and maul this dude. And he's gonna have to pay -- he's gonna have to pay for all this hard work, all this sacrifice I've made in this camp."

Jake added he's "100%" going to knock Diaz out ... but has no prediction on when it'll happen, 'cause he doesn't want to add any more pressure while he's in the ring.

Nate has only fallen twice via TKOs in his 20-year pro fighting career ...  one being a doctor's stoppage (vs. Jorge Masvidal), and the other coming against Josh Thomson in 2013, when the ref called the fight after a flurry of strikes.