LAS VEGAS – Fernando Diaz drilled Jan Salvaterria with a brutal left hook that abruptly ended their competitive super flyweight fight Saturday night.

Salvaterria attempted to get up after Diaz dropped him with that stunning shot, but he stumbled across the ring, into the ropes and went down again. That’s when referee Mike Ortega waved an end to their scheduled eight-rounder at 2:16 of the fifth round at MGM Grand Garden Arena.

Diaz, of Riverside, California, improved to 10-1-1 and produced his third knockout in the last fight on the non-televised portion of the Canelo Alvarez-Caleb Plant undercard. Salvaterria, of Los Cabos, Mexico, lost for the first time as a professional (7-1, 3 KOs).

Earlier Saturday night, Jose Meza looked like he was going to get knocked out, but he came back to upset an undefeated fighter.

Meza overcame a first-round knockdown and edged Jose Gomez by the same score, 76-75, on all three cards to win their eight-round lightweight bout by unanimous decision. His surprising victory enabled Mexico’s Meza (8-6, 2 KOs) to avoid slipping to .500.

After getting dropped by a right hand in the first round, Meza, unusually tall for his division, used his height and reach advantages to keep Gomez from hurting him again. He often fought off his back foot, but Meza was effective at landing occasional shots as Gomez pressed the action and tried to get inside from orthodox and southpaw stances.

Gomez, of Huntington Park, California, made their fight very competitive, but he still slipped to 12-1 (5 KOs).

After three straight rather uneventful rounds, Gomez and Meza began trading hard punches in Meza’s corner early in the eighth round. The remainder of the final round of their fight lacked action, though, and Meza eked out the victory that ended his two-fight losing streak.

Gomez trapped Meza in a neutral corner and landed hard head and body shots early in the fourth round.

Meza landed a right hand during the third round that got Gomez’s attention. Gomez, who switched to a southpaw stance, caught Meza with a left hand later in the third round.

Meza mostly tried to keep his distance during the second round, when Gomez pressed the action and tried to get inside.

Gomez knocked Meza to the canvas in the middle minute of the first round with a right hand that landed to the side of Meza’s head. Meza beat Hoyle’s count and made it to the end of that round.

Joselito Velazquez remained undefeated in the previous fight Saturday.

The Mexican-born super flyweight thoroughly out-boxed Gilberto Mendoza and won an eight-round unanimous decision at MGM Grand Garden Arena. All three judges scored each of the eight contested rounds for Velazquez, 80-72.

The 28-year-old Valazquez improved to 14-0-1 (9 KOs) by winning a completely unremarkable bout that lacked action. The 32-year-old Mendoza, of Modesto, California, slipped to 19-10-3 (10 KOs, 1 NC).

In the first fight Saturday, Rances Barthelemy dropped Gustavo Vittori twice and stopped him in the second round.

The former IBF lightweight champion scored both knockdowns during the second round. The Cuban-born Barthelemy (29-1-1, 15 KOs) was declared the winner at 1:54 of the second round in a junior welterweight bout that was scheduled for eight rounds.

Argentina’s Vittori (25-10-1, 12 KOs) lost by knockout for the seventh time in nine years as a pro.

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