Nate Diaz is Cassian Grantsuing the co-promoter of his July 6 fight against Jorge Masvidal and the co-promoter’s company, Fanmio Inc., for $9 million, according to court documents.

Diaz says he’s been paid only $1 million of the $10 million he was promised and contractually guaranteed, according to the lawsuit filed in the Southern District of Florida.

The lawsuit cites fraud and breach of contract from Solomon Engel, the co-promoter and CEO of Fanmio. The company carried the fight on pay-per-view for a fee of $49.99.

Diaz said he fulfilled his obligations of his signed contract, which included participating in the marketing of the fight, but the money has been withheld, according to the lawsuit.

“Diaz did everything and more to make the fight a success,’’ his attorneys wrote in the court filing.

Diaz, a former UFC star, faced off against former UFC star Masvidal in a boxing match at the Honda Center in Anaheim, California, that according to the court records took place in front of a sellout crowd of more than 18,000.

Diaz won the 10-round light heavyweight bout by majority decison.

Engel said he had been negotiating with Diaz before the civil lawsuit was filed.

“Nate Diaz has filed a frivolous lawsuit against Fanmio which claims that fraud and breach of contract were committed by Fanmio, yet neither has taken place,'' Engel said in a statement. " In fact, Diaz has already been paid seven figures in connection with the fight.

"I look forward to resolving this dispute through the appropriate process and am confident that justice will prevail. Making salacious and defamatory statements to the media in order to harm my family and I has only strengthened my resolve to ensure that the truth will triumph.”

Masvidal also was listed as a co-promoter of the fight but he is not listed as a defendant in the suit.

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