EXCLUSIVE

Logan Paul says his beef with KSI is 100% real — telling TMZ Sports he “hates” the YouTube star, and says he’s calling his shot in their upcoming boxing match. 

Logan and KSI came face-to-face during a heated news conference this past weekend — things got physical … and Logan is adamant the hatred ain’t just to sell tickets. 

“It’s real beef,” Paul told us on the way out of Catch in West Hollywood … “I hate the kid.”

The two will fight for real in August when they square off in Manchester — but, for now, it’s gonna be a LOT of trash talk. 

“I’m fighting a sack of potatoes. KSI, you suck.”

Paul says the fight isn’t just a big moment for YouTube stars who want to show they’re bigger than social media — it could also be a HUGE moment for the sport of boxing.