LAS VEGAS – Fernando Vargas’ namesake made quite an impression Saturday afternoon at the same venue where his famous father had his three biggest fights.

With the retired junior middleweight champion in his corner, Fernando Vargas Jr. needed less than three rounds to stop Kody Koboski in a middleweight match scheduled for four rounds on the non-televised portion of the Keith Thurman-Mario Barrios undercard at Mandalay Bay Resort and Casino’s Michelob ULTRA Arena.

Las Vegas’ Vargas, who improved to 5-0 and recorded his fifth knockout, dropped a game Koboski once apiece in the first and third rounds. Referee Kenny Bayless stopped the action at 1:46 of the third round, with an upright Koboski bleeding from his nose and taking too much punishment from the 25-year-old southpaw.

Koboski, of Ventura, California, lost for the first time in three pro fights (2-1, 2 KOs).

After dropping Koboski early in the first round, Vargas picked him apart with straight left hands in the second round and into the third round. Another straight left hand sent Koboski to the canvas for the second time in the bout early in the third round.

Vargas dropped Koboski with a left hand early in the first round. He dominated the first round and wobbled Koboski again with another left just before the bell sounded to end the opening round.

Once the fight was stopped, Vargas’ father pumped his fists to those that arrived early to watch his son in the venue formerly known as Mandalay Bay Events Center, where he lost his three biggest fights by technical knockout to Felix Trinidad, Oscar De La Hoya and Shane Mosley.

The younger Vargas, one of three sons from their fighting family who boxes, fought for the first time in the United States since he turned pro in December 2018. His first four professional fights took place in Mexico, most recently when he stopped Abel Villaba in the third round of a four-rounder July 23 in Los Mochis.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.