LAS VEGAS — Conor McGregor’s improbable challenge of Floyd Mayweather Jr. was a box-office smash.

There between 4 million and 5 million pay-per-view sales. An estimated 50 million people watched in the United States alone.

According to preliminary numbers compiled by Showtime PPV, the fight threatens the 4.6 million benchmark set by Mayweather’s 2015 fight with Manny Pacquiao. At $99.95 a buy, the fight is tracking to generate more than $450 million in television revenue, much of which will be shared by the two fighters.