With the fallout from the biggest boxing "fight of the century" still unfolding, another bout between two of the sport's biggest players has been announced not for the ring but for the courtroom.
Golden Boy Promotions is suing boxing Floyd Mayweather Jr's manager/advisor Al Haymon and his backers for $300m (£197m) for allegedly breaching antitrust laws.
The promotion company founded and run by legendary fighter Oscar De La Hoya claims that Al Haymon, who includes Mayweather Jr., Amir Khan and Keith Thurman in his stable of clients, has violated the Muhammad Ali Boxing Reform Act which prohibits managers from also acting as promoters.
De La Hoya explained:
During my 25 years in boxing, I have watched far too many fighters be chewed up, spit out and left with nothing to sit idly by while Mr. Haymon flaunts a federal law meant to protect those who put everything on the line to entertain fans of our sport.
The Muhammad Ali Act was passed to help fighters avoid the fate that bedeviled so many of our predecessors; and I will do everything in my power to ensure this crucial piece of legislation is upheld and followed.
The lawsuit has been brought against Al Haymon and his related companies and mutual fund manager Waddell & Reed Financial Inc and its related hedge funds.
Haymon is a Harvard economics graduate who, unlike De La Hoya, largely operates in the shadows of the sport but wields huge influence - he is likely to have earned over $10m from Mayweather's bout with Manny Pacquiao this weekend.
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Critics argue that he violates the Muhammad Ali act by using his influence to set up bouts on HBO between his own fighters and avoiding those belonging to other promotion companies. Indeed, last year promoters Main Event brought a lawsuit against Haymon with similar allegations about his role.
The nature of his influence in the sport has been brought under increased scrutiny following the establishment of Premier Boxing Champions, a terrestrial TV fight series whose existence has infuriated rivals such as Golden Boy.
In a statement the company took shots at Haymon by claiming:
Since the moment Al Haymon launched Premier Boxing Champions, he has repeatedly and brazenly broken the letter and spirit of the Muhammad Ali Boxing Reform Act that is meant to protect fighters from exploitation...
...Haymon calls himself a "manager" or an "advisor", yet Haymon and his myriad of companies are well known to arrange and contract for the bouts, the arenas, the sponsors and the television time - all duties of the boxing promoter.
Relations have been cool between the two parties after Golden Boy lost a number of its biggest fighters to Haymon earlier this year, following the departure of former chief executive Richard Schaefer.
This is not the first time Golden Boy has gone to war with a rival in the sport. In 2010 the company sued Top Rank - Pacquiao's promoters - for racketeering and fraud.