ARLINGTON, Texas – Marc Castro continued the strong start to his professional career Saturday night.

The accomplished amateur from Fresno, California, stopped Mexico’s Irving Macias Castillo in the fourth round of a lightweight bout that was scheduled for six rounds on the Canelo Alvarez-Billy Joe Saunders undercard at AT&T Stadium. The 21-year-old Castro (3-0, 3 KOs) landed the harder shots throughout their fight, caused swelling around Castillo’s right eye and targeted Castillo’s bloody nose.

Referee Rosario Solis stopped the action at 2:04 of the fourth round because Castillo had taken a lot of punishment in their one-sided fight. Castillo (9-2, 6 KOs) was still standing when Solis stepped between them.

Castro continued his assault on a battered but courageous Castillo for the first two minutes of the fourth round. Solis sensed Castillo was taking too much punishment, though, thus he stepped between them to stop the fight.

A left-right combination by Castro made Castillo retreat with just under a minute to go in the third round. By then, Castillo’s face was busted up, particularly his nose.

Castro picked apart Castillo with an array of punches in the first 30 seconds of the second round. Castillo fought back later in the second round and landed several shots of his own.

Castro caught Castillo with a right hand that backed him against the ropes about 45 seconds into the opening round. Castro continued to land jabs and right hands and bloodied Castillo’s nose in the first round.

In the previous fight Saturday night, Keyshawn Davis went the distance, but he remained unbeaten with ease.

The highly touted lightweight prospect was too fast and too skillful for Jose Antonio Meza throughout their six-round bout. The 22-year-old Davis won all six rounds on each scorecard – 60-54, 60-54 and 60-54 – and improved to 3-0.

Mexico’s Davis (6-5, 1 KO) hasn’t been knocked out in 11 professional fights.

Davis, of Norfolk, Virginia, made his pro debut February 27 after deciding to turn pro rather than represent the United States at the Summer Olympics in Tokyo.

Davis continued to out-box Meza during the sixth and final round, but he couldn’t hurt his durable opponent.

Davis connected with a right-left combination in the opening minute of the fifth round. Meza mounted some offense in the middle of the fifth round, but Davis connected with a left hook late in that round that made Meza hold him.

Davis snapped back Meza’s head with a stiff jab with about 15 seconds to go in the fourth round.

A right hand by Davis landed flush early in the second round. Davis defended himself well against Meza again in the second round.

Davis made Meza’s legs wobble when he landed a left hook late in the first round.

Earlier Saturday, a fighter from Alvarez’s hometown scored a quick knockout on his undercard.

Christian Alan Gomez Duran drilled Xavier Wilson with a left hook that sent Wilson to the canvas with 1:02 to go in the second round of their scheduled eight-round welterweight fight. Wilson struggled to reach his feet and stumbled once he got up.

Solis determined Wilson shouldn’t continue and stopped the action at 2:19 of the second round. San Antonio’s Wilson (11-3-1, 1 KO) lost by knockout for the first time in 15 professional fights.

Duran, of Guadalajara, Mexico, improved to 20-2-1 and produced his 18th knockout.

In the first undercard bout Saturday, Kelvin Davis got up from a knockdown late in the final round to win a unanimous decision over Jan Marsalek.

Davis (2-0, 1 KO), of Norfolk, Virginia, won their welterweight bout by the same score, 38-37, on all three cards. The judges each scored three of the four rounds for Davis, who went down when Marsalek landed a right hand with 33 seconds remaining in the fourth round.

Before that knockdown, Davis, a taller southpaw, mostly kept the Czech Republic’s Marsalek (8-3, 7 KOs) at the end of his jab and landed straight left hands. Most notably, Davis nailed Marsalek with a left hand that made Marsalek cover up just before the second round ended.

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