Terence Crawford, who has not been beaten, became the first man to stop Shawn Porter in defense of his WBO welterweight title on Saturday in Las Vegas.
Unbeaten Crawford knocked Porter down twice in the 10th before Porter’s father and trainer Ken Porter stepped in to call off the fight.
The 34-year-old felled Porter initially with a left uppercut on the button that buckled his knees.
It was all over 1:21 of the round, when Crawford’s overhand right to the side of the head sent Porter to the canvas for a second time, prompting Porter’s father to lean over the ropes and ask the referee to halt the contest.
Crawford improved to 38-0 with 29 wins by knockout, while Porter suffered the fourth loss of his career, falling to 31-4-1 with 17 KOs.
Crawford moved to 16-0 in world championship fights and extended his streak of winning inside the distance to nine straight bouts.
Errol Spence Jr, the IBF and WBC titleholder who has long been Crawford’s most desired rival, left his ringside seat and walked out during Porter’s demise.