LAS VEGAS – Delante “Tiger” Johnson saw blood during the third round of his pro debut Saturday.

It was his own blood and it inspired Johnson to take out Antonius Grable on the Terence Crawford-Shawn Porter undercard at Mandalay Bay Resort and Casino’s Michelob ULTRA Arena. Johnson, a 2016 U.S. Olympian from Cleveland, wobbled Grable after suffering a cut late in the third round, dropped him in the fourth round and eventually made referee Allen Huggins stop their welterweight bout with barely a minute left in it.

Huggins stopped the action at 1:54 of the fourth and final round of the first fight of an eight-bout card. Grable (3-2-1, 3 KOs), of Sarasota, Florida, was on his feet when Huggins halted the action, but he had just been backed into the ropes with another hard right hand from Johnson, who was ahead by the same score, 30-27, on all three cards entering the fourth round.

Johnson dropped Grable with a left hook just after the halfway point of the fourth round.

The 23-year-old prospect began fighting more aggressively after he suffered a cut over his left eye with just under a minute remaining in the third round. As soon as a ringside physician looked at his cut and the action resumed, Johnson drilled Grable with a right hand that buckled his legs.

Earlier in the third round, Johnson drilled Grable with a right hand that backed him up. Johnson previously took a flush right hand from Grable during the second round without incident.

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