LAS VEGAS – Unbeaten Mexican Aaron Silva pulled off a slight upset on the Canelo Alvarez-Dmitry Bivol undercard Saturday at T-Mobile Arena.

Silva hurt previously unbeaten Alexis Espino with a left hook a little less than a minute into the fourth round. Sensing Espino was ready to go, Silva landed several additional flush right hands and left hooks up top and mixed in two lefts to the body, until referee Celestino Ruiz stepped between them and stopped their eight-round super middleweight match at 1:17 of the fourth round.

Las Vegas’ Espino (9-1-1, 6 KOs), who was backed against the ropes when their fight ended, protested Ruiz’s stoppage. Monterrey’s Silva improved to 10-0 and produced his seventh knockout.

The 22-year-old Espino had some success during the first two rounds, but the 24-year-old Silva started to land the harder punches during the third round and bloodied Espino’s nose.

In the bout before Silva’s victory, Elnur Abduraimov was entirely too strong for Manuel Correa.

The powerful southpaw from Uzbekistan dropped the previously unbeaten Correa three times in the second round and stopped him late in that round. Referee Robert Hoyle stopped a junior lightweight fight schedule for eight rounds at 2:43 of the second round, as soon as Correa was knocked down for the third time.

The trouble began for Miami’s Correa (11-1, 7 KOs) when Abduraimov dropped him with a straight left hand with 2:13 to go in the second round. Correa reached his feet quickly, but Abduraimov unloaded a barrage of power shots on him until a right hook to the side of Correa’s head knocked him to the canvas again, this time with 1:02 to go in the second round.

Correa courageously got up again and tried to keep away from an aggressive Abduraimov (9-0, 8 KOs).

Abduraimov then hit him with another left hand that sent Correa down, into the ropes. That’s when Hoyle stepped in to stop their fight.

In the first fight on the undercard Saturday, 19-year-old Mexican junior welterweight prospect Fernando Molina got up from a sixth-round knockdown and defeated Ricardo Valdovinos by split decision in a six-rounder.

Guadalajara’s Molina (8-0, 3 KOs) built an early lead and defeated San Diego’s Valdovinos (8-2, 5 KOs) on the scorecards of judges Eric Cheek (58-56) and Kermit Bayless (57-56). Judge Don Trella scored three rounds apiece for Molina and Valdovinos, but Valdovinos won by a point on his card, 57-56, due to that sixth-round knockdown.

An aggressive Valdovinos started to land right hands during the fourth and fifth rounds, when the course of their fight changed. He later caught Molina with a left hook and Molina lost his footing, which referee Michael Ortega counted as a knockdown with 1:20 to go in the sixth round.

Molina mostly boxed successfully off his back foot and worked well off his jab during the first three rounds.

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