By Keith Idec

RENO, Nevada – Xander Zayas made a sensational professional debut Saturday.

The 17-year-old high school senior knocked down Genesis Wynn twice within the first minute and 21 seconds of their fight and knocked him out in the first round on the Shakur Stevenson-Joet Gonzalez undercard at Reno-Sparks Convention Center. Referee Jay Nady immediately waved an end to their scheduled four-round welterweight fight after Wynn went down a second time, with 1:36 to go in the opening round.

At 16 years old, Zayas was the youngest fighter ever to sign a contract with Hall-of-Fame promoter Bob Arum’s company, Top Rank Inc. The 11-time national amateur champion from Puerto Rico showed signs in his first professional fight why Arum and his matchmakers are high on the 5-feet-10, 147-pound prospect.

Zayas, a resident of Davie, Florida, drilled Wynn with a straight right hand that sent him to the seat of his trunks 55 seconds into the first round. Wynn was able to get up, but Zayas attacked again and dropped him a second time after landing a right to the head, followed by a right to the body.

Denver’s Wynn, 31, fell to 1-1.

In the bout before Zayas’ victory, Reno native Wilfred Mariano out-boxed Sean William Cerveny to win a unanimous decision in their four-round welterweight bout.

Each of the three judges scored all four rounds for Mariano, a University of Nevada graduate who works full-time at a FedEx center in Reno. The 25-year-old Mariano (2-0, 1 KO) won 40-36 on each of their scorecards.

San Antonio’s Cerveny, also a mixed martial arts fighter, slipped to 0-2 as a boxer.

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