LAS VEGAS – Emiliano Vargas viciously took out Rafael Jasso on the Devin Haney-Vasiliy Lomachenko undercard Saturday at MGM Grand Garden Arena.

The 19-year-old Vargas, the youngest son of former junior middleweight champion Fernando Vargas, landed various head and body shots before he drilled Jasso with a left to his midsection that sent Jasso to the canvas just before the midway mark of the second round. Jasso tried to get up, but he couldn’t beat referee Harvey Dock’s count.

Their scheduled four-round lightweight bout was stopped 1:41 into the second round.

Las Vegas’ Vargas improved to 5-0 and recorded his fourth knockout. Jasso, of Fresno, Texas, lost for the first time as a pro (3-1, 1 KO).

In the previous fight Saturday, Floyd Diaz battered and bloodied Luis Fernando Saavedra for much of the eight rounds they fought.

The undefeated Diaz continually caught Saavedra with right hands and jabs, and although he couldn’t put Saavedra down, he easily won their junior featherweight fight on points. The resilient, rugged Saavedra displayed toughness and never stopped coming forward, but Las Vegas’ Diaz (9-0, 3 KOs) was much more active and accurate over the course of their fight and won by wide distances on all three scorecards.

Judges Lisa Giampa (80-72) and Chris Migliore (80-72) scored their fight a shutout for Diaz. Judge Patricia Morse Jarman scored one round for Saavedra, who lost 79-73 on her card.

Saavedra (9-9, 3 KOs), of Santa Paula, California, has lost seven of his past nine bouts, but he has not been knocked out in nine years as a pro.

Referee Allen Huggins called for time with 33 seconds to go in the sixth round, so that a ringside physician could check the nasty gash around Saavedra’s left eye. Otherwise, however, their fight amounted to eight rounds of sustained action controlled mostly by Diaz.

Earlier Saturday, Abdullah Mason methodically broke down Desmond Lyons to remain undefeated.

The 19-year-old lightweight prospect from Cleveland attacked Lyons to the head and body until referee Robert Hoyle halted their fight 32 seconds into the sixth round. Lyons was still standing when Hoyle stopped the bout, but the left-handed Mason’s punches had taken a toll on him and Lyons didn’t complain about Hoyle’s decision.

Mason (8-0, 7 KOs) didn’t drop Lyons, but he picked apart the game Lyons as the rounds proceeded. The 24-year-old Lyons (8-3, 2 KOs), of North Augusta, South Carolina, lost inside the distance for the first time in 11 professional fights.

A right to the body by Mason hurt Lyons badly early in the sixth round. Mason then hammered Lyons to the body and head until Hoyle came between them to prevent Lyons from taking more damage.

Mason buzzed Lyons with a left hand when there were about 35 seconds to go in the fifth round. He backed Lyons into a neutral corner and tried to finish him off, but Lyons moved, held and eventually made it to the bell to end the fifth round.

Mason knocked Lyons off balance with a straight left when there were about 40 seconds to go in the fourth round. Mason landed a hard combination as Lyons came forward a little less than a minute into the fourth round.

Lyons pressed Mason as soon as their bout began, but Mason responded to that pressure well and later backed up Lyons.

In the first fight Saturday, Amari Jones became the first fighter to stop Pachino Hill.

The undefeated middleweight prospect battered Hill late in the fifth round and then hurt him again in the sixth round. Referee Mike Ortega stepped between them to stop the action at 1:16 of the sixth and final round.

Hill (8-3-1, 6 KOs) remained on his feet at the time of the stoppage, but Jones rocked him with a right hook and then back-to-back straight left hands as Hill backed into the ropes.

The 21-year-old Jones improved to 9-0 and produced his eighth knockout. Las Vegas’ Jones is trained by Bill Haney, Devin’s father and trainer.

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