Floyd Mayweather Jr lashed out at the judges after Badou Jack's super-middleweight unification bout with James DeGale ended in a majority draw on Saturday.
IBF champion DeGale and WBC belt-holder Jack could not be separated at the Barclays Center, with two of the three judges who were ringside in Brooklyn scoring the contest 113-113, the other having awarded it 114-112 in DeGale's favour.
And Jack's promoter Mayweather, the undefeated former five-division world champion, was one of the few observers to take issue with the outcome following an entertaining and evenly matched bout.
"It's the second time in a row Badou Jack has gotten a bad decision," Mayweather said, referring to a draw against Lucian Bute in April last year.
"James DeGale is a hell of a fighter, but he didn't win. I respect him as a fighter, but Badou Jack was the better man.
"I'm the promoter, this is my fighter and this is the second time this has happened. Two times in a row. It's all about being fair. At the end of the day, I don't know what the judges are looking at.
"When I fought Canelo [Alvarez, in 2013] one of the judges had him winning. This is bad for boxing when it's all said and done."
Mayweather also put a stop to suggestions of a rematch, despite both fighters expressing their interest soon after the bell.
"The thing with boxing is, if they can't get it right the first time, they're not going to get it right the second time," Mayweather said.
"We don't need the second time around.
"Me and Badou Jack, we already communicated. The goal was to fight this fight, then for him to move up to light heavyweight. He's a big super middleweight.
"How I'm feeling, I don't really want to come back and fight on the east coast anymore."