Mark Zuckerberg has said he is abandoning plans for a ring-cage match with Elon Musk, claiming the Tesla chief executive is "not serious".
They apparently agreed to a fight in June, when Musk tweeted that he was "up for a cage match."
Zuckerberg responded by writing "send me location". However, on Sunday he said on social networking platform Threads: "I think we can all agree that Elon is not serious and it's time to move on."
"I suggested a real meeting. Dana White (executive director of The Ultimate Fighting Championship) offered to make the match a legitimate charity contest," he then added.
"Elon won't confirm a date, then says he needs surgery, and now he's asking me to do a workout in my backyard," Zuckerberg said.
"If Elon ever gets serious about a real date and an official event, he knows how to contact me. Otherwise, time to move on. I will focus on racing people who take the sport seriously," he concluded.
Zuckerberg is trained in martial arts. Earlier this year, he posted about finishing his first jiu jitsu tournament.
Tensions have been high between the two billionaire tech companies following the launch of Threads, a Twitter-like app.