Undefeated Mexican junior lightweight standout Miguel Berchelt needed only one round to dispatch Carlos Claudio in his American debut on the undercard of the Brandon Rios-Mike Alvarado undercard on Saturday at the Mandalay Bay in Las Vegas.

Berchelt (17-0, 14 KOs) needed only 1:53 to dispatch Carlos Claudio (15-10-3, 8 KOs) ,of Kissimmee, Fla. Berchelt landed a bevy of power shots early, then eventually stunned Claudio, sending him to the ropes. Berchelt wasted no time jumping on his opponent, landing a signature Oscar De La Hoya style flurry of punches that forced referee Kenny Bayless to stop the fight.

Highly touted 2012 U.S. Olympian Jose Ramirez (2-0, 2 KOs) made quick work of Hastings, Neb.’s Charlie Dubray, dropping him twice in the opening round en route to a TKO. Ramirez bounced a right hand off the top of Dubray’s head early in the round, resulting in a knockdown. Dubray returned to his feet and Ramirez jumped on him, unleashing a furious body attack before referee Robert Byrd halted the bout at 1:06.

Las Vegas welterweight Michael Finney (11-0, 9 KOs) scored a rare highlight-reel body shot knockout against Osvaldo Rojas (7-3-2, 2 KOs) of Portland, Ore., in the fifth round.

Rojas proved to be a game challenge, landing some hard shots throughout the fight. Finney, however, turned in one of his better performances as a pro, showing an improvement in his combination punching. In the fourth round, Finney hurt Rojas, staggering him still for a few seconds. In the fifth, Finney and Rojas traded hard blows, and Finney came back with an absolutely brutal left hook to the body. Rojas went down like he had a full clip unloaded in him, and was counted out by Vic Drakulich at 49 seconds of the round.

Former amateur standout Tramaine Williams (6-0, 2 KOs) of New Haven, Conn., boxed a four-round shutout of Roswell, N.M.’s John Herrera (4-6-1, 2 KOs) in their junior featherweight contest. Williams was just many classes above his opponent, landing combinations in sixes and sevens with regularity. Scores were 40-36 across the board.

In the most exciting bout of the untelevised undercard, heavyweights Brett Rather (3-0) of Las Vegas and Juan Guajardo (2-1, KO) of McAllen, Tex.,engaged in a four-round slugfest. Rather got dropped in the opening round but was able to come back and outhustle Guajardo to a narrow decision victory, winning 38-37 on all three cards.

Las Vegas junior welterweight Juan Heraldez (5-0, 4 KOs) earned a dominant four-round decision over Roberto Lopez (4-5-2, KO) of Kissimmee, Fla. Heraldez dropped Lopez with a left hook upstairs in the second round en route to a 40-35 victory on all three scorecards.

Junior welterweight Manuel Lopez (2-0, 2 KOs), a stablemate of main eventer Mike Alvarado, scored a second round stoppage of Las Vegas-based Jason Tresvan (0-2) in their scheduled four-round bout. Lopez overwhelmed Tresvan in the second round, battering him until referee Kenny Bayless stopped the fight at 2:06.

Photo: Chris Farina-Top Rank