Doug Kezirian says oddsmakers are confident the Mayweather-McGregor fight will break the boxing record of $50 million in wagers. (2:11)

Big bets were coming in fast and furious in the hours leading up to the Floyd Mayweather-Conor McGregor megafight, highlighted by two more $1 million bets made Saturday on the favored boxing champion.

That brought the total of $1 million bets on the fight to six. In comparision, Las Vegas bookmakers recorded just one for February's Super Bowl LI.

The MGM and South Point sportsbooks each reported taking $1 million bets on Mayweather on Saturday afternoon. The Wynn sportsbook also revealed that it had taken two million-dollar bets on Mayweather on Friday, according to executive director Johnny Avello.

The Westgate Las Vegas SuperBook began the day with Mayweather at -700, but had moved the price down to -550 by midafternoon. About three hours before the fight, Mayweather's odds had dropped to their lowest yet, at -460. About an hour before the fight was scheduled to begin, Mayweather was back up to -500 with McGregor at +375.

The amount of money being wagered on the fight was stunning bookmakers. By late Saturday afternoon, more bets had been placed on just McGregor at William Hill's Nevada sportsbooks than were placed on the New England Patriots in Super Bowl LI, according to vice president of marketing Michael Grodsky.

Twice as much money had been bet on Mayweather-McGregor than had been bet on Mayweather-Manny Pacquaio at William Hill. The 2015 Mayweather-Pacquiao fight was the most heavily bet boxing match ever in Nevada, generating an estimated $60 million in handle.

Even with the big bets on Mayweather, most sportsbooks were still facing sizable liability on the underdog McGregor. From 11 a.m. to 2 p.m. PT Saturday, Caesars Palace sportsbooks wrote more than 1,200 bets on the fight. Ninety-two percent of those bets were on McGregor.

Nevada sportsbooks were estimating that as much as $80 million could be bet on the fight statewide, making it the most heavily bet boxing match ever.

Statewide bets in Nevada on Super Bowl LI between the Patriots and Atlanta Falcons reached $138.4 million.