LAS VEGAS – Anthony Dirrell delivered a performance Saturday night befitting a former champion who wants another title shot.

The two-time ex-WBC super middleweight champ viciously knocked out overmatched Marcos Hernandez in the fourth round of Showtime Pay-Per-View’s co-feature before Canelo Alvarez and Caleb Plant entered the ring for their 12-round main event at MGM Grand Garden Arena. The 37-year-old Dirrell (33-2-2, 25 KOs), of Flint, Michigan, uncorked a right uppercut that knocked Hernandez flat on his back about 12 seconds into the fourth round.

Hernandez (15-5-2, 3 KOs), of Fresno, California, beat referee Celestino Ruiz’s count, but he stumbled when Ruiz instructed him to prove he could continue. Ruiz understandably stopped the action 22 seconds into the fourth round.

Dirrell bounced back from a 12-round draw with Kyrone Davis (16-2-1, 6 KOs) in his last fight, which took place February 27 in Los Angeles. Hernandez defeated previously unbeaten Mexican prospect Jose Armondo Resendiz (12-1, 8 KOs) in his previous appearance, a 10-rounder September 5 in Minneapolis.

Before finishing Hernandez early in the third round, Dirrell drilled Hernandez with a left hook got Hernandez’s attention in the third round. Dirrell landed the harder shots during a second round he clearly won thanks in large part to his overhand right.

Dirrell unloaded a barrage of power punches on Hernandez as soon as the bell rang to start that fight. Hernandez backed into a neutral corner and seemed surprised by Dirrell’s aggression, but he eventually adjusted and got back into the fight later in the first round.

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