SAN ANTONIO – Bakhram Murtazaliev maintained his position as the IBF’s mandatory junior middleweight challenger on another Jermell Charlo undercard Saturday night.

Russia’s Murtazaliev battered a courageous Khiary Gray for most of their eight-round middleweight match and won their non-televised bout by unanimous decision. Murtazaliev (19-0, 14 KOs) won by scores of 79-73, 79-73 and 78-74 on the Charlo-Brian Castano undercard at AT&T Center.

Murtazaliev’s mandated IBF title shot is overdue and he expects to challenge Charlo next if he beats Castano later Saturday night in their “Showtime Championship Boxing” main event. Murtazaliev accepted a second straight slot on Charlo’s undercard, which helped allow Charlo to proceed with a full 154-pound title unification against Argentina’s Castano.

Gray (16-6, 12 KOs), of Worcester, Massachusetts, is 2-5 in his past seven fights.

Gray blasted Murtazaliev with a left hook in the middle of the eighth round that got Murtazaliev’s attention. By then, though,

Murtazaliev kept pressing the action in the sixth and seventh rounds and landed numerous overhand rights. A left hook by Murtazaliev moved Gray backward just after the midway mark of the seventh round.

A left hook to the body by Murtazaliev early in the fifth round made Gray wince and move away from him.

Murtazaliev belted Gray with a left hook early in the fourth round. Murtazaliev spent most of the remainder of that round landing hard right hands against his game opponent.

Murtazaliev hammered Gray with a right hand that knocked Gray off balance early in the third round. A counter right hand by Gray wobbled Murtazaliev later in the third round, however, and encouraged Gray to continue throwing hard shots at him.

Murtazaliev landed a low right hand later in the third round that caused a break in the action.

Gray landed enough flush punches to keep Murtazaliev honest during the second round. Murtazaliev continually landed hard right hands in that round, though, and bloodied Gray’s nose.

Murtazaliev knocked Gray off balance in the middle minute of the first round with a right hand to the side of Gray’s head. It was clear throughout that opening round that Murtazaliev was the harder puncher.

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