Emiliano Vargas’ opponent lasted 9½ rounds longer Saturday night than his previous conquest.

Vargas stayed sharp throughout his bout while landing numerous punishing head and body shots on Jonathan Montrel, but the durable Montrel made it to the final bell on the Rafael Espinoza-Arnold Khegai undercard at Arena Coliseo in San Luis Potosi, Mexico.

Las Vegas’ Vargas, a son of former junior middleweight champ Fernando Vargas, easily won their 10-round bout by scores of 100-89, 99-90 and 99-90.

The 21-year-old Vargas (16-0, 13 KOs), one of boxing’s top prospects, went 10 rounds for the first time. The first two unanimous points wins of the developing junior welterweight’s career were six-rounders.

“I knew he was a tough fighter,” Vargas said. “I didn’t want to get too crazy. I just wanted to take my time. I’m glad I got this experience, and we’re on to the next challenge.”

The toughness Montrel demonstrated was admirable. New Orleans’ Montrel (19-4, 13 KOs), who has been knocked out only once, didn’t test anything other than Vargas’ patience and endurance, though.

Montrel managed to connect occasionally as Vargas aggressively pressed the action. He just couldn’t hurt Vargas or prevent him from unloading hard shots to his head and body.

An overhand right by Vargas staggered Montrel with approximately 1:10 to go in the fifth round. Montrel remained on his feet and proved Vargas would be in for a longer night than anticipated.

Vargas delivered a “Knockout of the Year” candidate in his last fight – a first-round demolition of Alexander Espinoza (20-4-1, 9 KOs) on July 26 in The Theater at Madison Square Garden in New York.