LAS VEGAS – Kevin Johnson beat another undefeated fighter Saturday night.

The veteran junior welterweight from Detroit battered Rock Myrthil until Myrthil’s trainer threw in the towel late in the ninth round of a welterweight fight scheduled for 10 rounds. Johnson improved to 10-2 and recorded his sixth knockout on the non-televised portion of the Brandon Figueroa-Stephen Fulton undercard at Park MGM’s Dolby Live.

It was clear very early in this bout between 29-year-old boxers promoted by Floyd Mayweather’s company that Johnson simply was too strong for Myrthil. He kept the younger, unbeaten boxer on his back foot for almost all of their fight, dropped him in the fourth round and eventually convinced Myrthil’s trainer that he couldn’t come back to win.

Johnson hurt Myrthil yet again with another left hook early in the ninth round. Myrthil tried his best to survive, but his trainer threw in the towel because he took several additional power punches and didn’t throw anything back.

Referee Kenny Bayless stopped the action at 2:51 of the ninth round.

A left hook by Johnson snapped back Myrthil’s head early in the eighth round and forced him to move around the ring. Johnson rocked him again with another left hook late in the eighth round.

Johnson kept Myrthil on his back foot throughout the sixth and seventh rounds, but Myrthil managed to avoid getting hurt again in either of those two rounds.

Multiple left hooks and a right hand seemed to buzz Myrthil again late in the fifth round. Myrthil moved away from Johnson as best he could, but he clearly was wearing down at that point.

Johnson nailed Myrthil with a right hand and then a left hook that forced Myrthil to hold him early in the fourth round. Less than a minute later, Johnson drilled Myrthil with a left hook that sent him to the seat of his trunks.

Myrthil answered Bayless’ count in plenty of time, though he struggled to keep Johnson off of him once the action continued.

Johnson caught Myrthil with a left hook to his head that made Myrthil hold him early in the third round.

Johnson was the aggressor again during the second round, when he consistently landed the harder shots to Myrthil’s head and body.

Johnson pressured Myrthil as soon as their fight started, but he didn’t land anything clean. Myrthil connected with a right hand as stood in the center of the ring later in the first round, but Johnson unloaded with combination of power punches several seconds later.

Johnson landed another flush right hand that backed up Myrthil in the final minute of the first round.

In the previous bout Saturday night, Kenny Davis Jr. edged Nelson Hampton by split decision in a six-round lightweight fight.

Two judges – Chris Migliore and Ricardo Ocasio – scored their back-and-forth fight for Davis by the same score, 58-56. The other judge, Patricia Morse Jarman, scored it 58-56 for Hampton.

Davis (8-2-1, 3 KOs), of Reno, Nevada, has won eight straight fights since suffering back-to-back fourth-round, unanimous-decision defeats in September 2017 and April 2018, respectively. Hampton (7-5, 4 KOs), of Donna, Texas, has lost three fights in a row.

In the opening fight on the Figueroa-Fulton undercard, Albert Gonzalez landed the harder shots and was the busier boxer during his pro debut, which resulted in a four-round, unanimous-decision victory over Chamar Flores. Gonzalez, a junior featherweight from Moreno Valley, California, recorded a shutout, 40-36, on all three scorecards against Flowers (1-2), of Washington, D.C.

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