Emiliano Vargas barely went three combined minutes through his first two pro bouts.

All four rounds were needed to secure his latest victory.

The second-generation boxer went the distance for the first time in his young career, outclassing Francisco Duque in a well-earned, unanimous decision victory. All three judges scored the contest 40-36 for Vargas in the ESPN+ aired opening bout Friday evening from Desert Diamond Arena in Glendale, Arizona.

At just 18, Vargas is the youngest fighting son of former two-time junior middleweight champion Fernando Vargas, though regarded as the most talented of the bunch. His in-ring gifts immediately caught the eye of Top Rank, who signed the lightweight to a promotional contract prior to his second-round knockout of Julio Martinez last November 12 in his adopted hometown of Las Vegas.

A tougher test was provided on Friday, as Duque remained upright and in the pocket throughout the four-round affair. Vargas made key mid-fight adjustments once he realized the fight would go rounds.

Vargas switched between orthodox and southpaw, landing power punches from both sides including a flush left hook in his best moment of the fight in the fourth and final round. Duque (1-2, 0KOs)—who was over the 134-pound contracted limit but still permitted to fight—took the shots well and managed to occasionally have his say in his best effort to test Vargas’ young fighting heart.

The win advanced Vargas’ record to 3-0 (2KOs).

Also on the show, Lindolfo Delgado advanced to 17-0 (13KOs) with an eight-round, unanimous decision victory over battle-tested Clarence Booth. Scores of 80-71, 79-72 and 79-72 landed in favor of Delgado, a 2016 Olympian for Mexico who scored an eighth-round knockdown to seal his latest victory.  

Booth (21-7, 13KOs) came out well-intended, using his three-inch reach advantage to keep Monterrey’s Delgado at bay. The 35-year-old from Saint Petersburg enjoyed success with his jab throughout the bout, though he was ultimately outgunned by the heavier handed Delgado who was dangerous with his lead right hand.

Delgado nearly closed the show in the eighth and final round. A jab pushed Booth into position for a straight right hand to produce the bout’s lone knockdown. Booth was on unsteady legs for the balance of the fight but was able to make it to the bell, as Delgado has now gone the distance in each of his two starts.

The final bout of the ESPN+ preliminary undercard saw Andres Cortes outpoint Luis Melendez over ten painfully dull rounds. Judges Esther Lopez (100-90), Pat Russell (100-90) and Chris Wilson (100-90) all scored every round for Las Vegas’ Cortes (19-0, 10KOs), who overcame a deep cut in his left eyelid to preserve his unbeaten record. Melendez (17-3, 13KOs) suffered his second straight defeat on a night where he seemed more interested in making things ugly than in pursuing the upset. Both fighters were cut in round six from headbutts, with Cortes’ wound deep enough to where his corner questioned whether it warranted the fight being stopped and going to the scorecards.

Cortes braved through the rest of the fight, thanks to the superior work put in by legendary cutman Jacob ‘Stitch’ Duran, The cut was no longer a factor, though Cortes was forced to contend with Melendez’s grappling tactics which often drew the scorn of referee Tony Zaino.

Headlining the seven-fight card, Mexico’s Emanuel Navarrete (36-1, 30KOs) and Australia’s Liam Wilson (11-1, 7KOs) meet for the vacant WBO junior lightweight title.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox