CSI Sports Events filed a federal lawsuit on Thursday against Floyd Mayweather, asking a judge to stop his June 27 fight against Mike Zambidis in Greece before the bell rings. The company is seeking a permanent injunction and $6.65 million in restitution, turning a scheduled bout next weekend into a court fight that could move faster than the promotion can.
The legal push matters now because Judd Burstein said he planned to file an emergency injunction application in federal court to try to halt the bout. CSI says the dispute is not just about one fight in Greece; it is about whether Mayweather can walk away from earlier deals and still proceed with a separate opponent while those contracts remain in place.
CSI says it had already locked in Mayweather through agreements tied to his planned fights with Mike Tyson and Manny Pacquiao. In the company’s account, CSI and Frist Apex Ventures reached a deal on Aug. 10, 2025, for a Tyson-Mayweather fight in the spring of 2026, with Frist Apex acting as Mayweather’s representative. CSI also says it agreed to pay Mayweather $14 million to fight Mike Tyson, including a $2 million advance, and later signed a separate exclusive agreement in November 2025 for a fight after Tyson. For the Pacquiao side of the deal, CSI says Mayweather would receive $35 million if Manny Pacquiao was the opponent, 20% of any PPV revenue if Pacquiao was the opponent, a $50 million buyout if the fight was not on PPV, or $20 million to fight a different opponent if Pacquiao were unavailable.
That is where the fight over the paperwork turns sharp. CSI says Mayweather entered into a December 2025 agreement with EverWonder for the Pacquiao fight on Netflix for $24.75 million, including a $2.75 million advance and a potential $3.75 million bonus, while CSI and EverWonder were still working out how to handle the competing claims. Burstein said Tyson would go first and CSI would allow Pacquiao to go forward in the fall in the Sphere televised by Netflix with CSI getting full billing rights, and he said Frist Apex needed to repay an advance as part of CSI's deal with EverWonder. CSI also alleges that Mayweather refused to tweet an announcement of his return to boxing in November 2025 because he was in the process of selling those rights to a third party.
The new filing says CSI later learned of a third fight agreement for Mayweather-Zambidis while the EverWonder talks were still underway, and that the Zambidis bout would violate CSI’s exclusive rights with Mayweather. Burstein said, “We were prepared to go forward,” and added that Mayweather had agreed to give CSI exclusive rights to the fight after Pacquiao. Mayweather is also suing Frist Apex Ventures in a separate civil case for aiding and abetting breach of fiduciary duty, adding another layer to a dispute that now spans contracts, representation and control of the rights around his fights. If the court acts before June 27, the question will not be whether Mayweather can fight in Greece, but which deal still has legal force when the calendar runs out.
