Elon Musk Throws Podcaster Lex Fridman, Training For Mark Zuckerberg Fight

Elon Musk is already hitting the training mats in anticipation of his huge fight with Mark Zuckerberg ... throwing and slamming a famous black belt who recently trained with Elon's fellow billionaire.

Popular podcaster Lex Fridman says he had an impromptu training session with Elon on Monday, sharing a photo of Elon slamming him to the ground.

Lex, a black belt in jiu-jitsu, says he came away super impressed with Elon's fighting prowess.

"I'm extremely impressed with his strength, power, and skill, on the feet and on the ground," Lex said. "It was epic. It's really inspiring to see Elon and Mark doing martial arts, but I think the world is served far better if they train martial arts but not fight in the cage."

Don't get it twisted, Lex wants to see Elon and Mark do battle ... just like everyone else.

Lex adds ... "That said, as Elon says, the most entertaining outcome is the most likely... I'm there for them, no matter what."

It's interesting to see Elon and Lex training ... Lex recently had Mark on his podcast, and they trained some jiu-jitsu.

In addition to Lex, Elon's accepted an offer to train with UFC legend Georges St-Pierre ... while Jon Jones recently offered Mark his services.

As TMZ Sports first reported, Dana White told us both sides are for real about getting in the Octagon together ... and now Elon's showing just how serious he is.