LAS VEGAS – One of boxing’s most promising prospects regained some momentum Saturday after a weigh-in debacle late last year in Atlantic City.

Curmel Moton, an 18-year-old lightweight promoted by Floyd Mayweather, stopped Frank Zaldivar in the third round of an eight-rounder on the David Benavidez-David Morrell Jr. undercard at T-Mobile Arena. Referee Harvey Dock stepped between them as Moton hammered Zaldivar with punishing punches to his head and body and halted the action at 1:51 of the third round.

Zaldivar never went down, but Dock spared him a more abusive beating by stopping their one-sided fight when he did. Zaldivar’s trainer tried to get the bout stopped several seconds earlier, but Dock’s back was turned to a Nevada State Athletic Commission inspector who tried to get the veteran referee’s attention.

Las Vegas’ Moton improved to 7-0 and recorded his sixth knockout. Zaldivar, a Miami resident raised in Cuba, lost his second straight fight (5-2, 3 KOs, 1 NC).

A round before Moton overwhelmed Zaldivar with power punches, Moton attacked Zaldivar’s body during the second round. A left hook to Zaldivar’s body made him take a step backward with about 35 seconds to go in the second round.

By then, Zaldivar didn’t offer nearly as much resistance as he did during the first round. Zaldivar came out swinging when the opening bell rang, but Moton’s commitment to body work started building the foundation for a stoppage two rounds later.

Moton met his contractual obligation Friday by coming in at 134.8 pounds, below the lightweight limit of 135 pounds for his fight against Zaldivar.

He caused controversy the day before his last fight by weighing in at 145.8 pounds November 29, almost 13 pounds above the contracted maximum of 133. Moton made matters worse by blaming New Jersey’s State Athletic Control Board for his unprofessionalism, though he later apologized in a letter to longtime New Jersey commissioner Larry Hazzard.