Elon Musk is pulling out all the stops in preparation for a fight with Mark Zuckerberg -- the Twitter honcho just accepted a training offer from UFC legend Georges St-Pierre!!
The shocking development in the potential billionaire brawl went down on Monday ... when Elon replied to GSP's public pitch to lend a hand in beating Zuck to a pulp in the Octagon.
"I'm a huge fan of yours and it would be an absolute honor to help you and be your training partner for the challenge against Zuckerberg ud83dudc4aud83dude01," GSP said on Twitter .