Unbeaten Jermell Charlo knocked out Charles Hatley just 32 seconds into the sixth round on Saturday to retain his World Boxing Council super welterweight title in an all-American showdown.
Charlo landed a flurry of punches to open the sixth round, the decisive one a stunning right hook to the chin that caused the challenger to fall forward to the canvas, prompting an immediate stoppage.
"I knew Charles Hatley goes down sometimes and gets back up -- he's a warrior and won't go down easily," Charlo said. "I knew I had to be a lion in there."
Charlo improved to 29-0 with 14 knockouts while Hatley fell to 26-2 with one drawn.
Asked after the triumph whom he might like the fight next, Charlo said was interested in a unification bout against compatriot Jarrett Hurd, the International Boxing Federation champion.
Charlo's unbeaten brother, Jermall, vacated the IBF crown in the 154-pound weight class two months ago to advance into the middleweight ranks, Hurd winning a February fight to claim the crown.
Charlo, making his first title defense, had not fought since last May, when he won the crown with an eighth-round knockout of US Virgin Islands fighter John Jackson.
The bout was a matchup of Texas rivals, but Houston's Charlo, 26, dominated Dallas-based Hatley, 31.
Charlo, who suffered a cut over his left eye in a second-round clash of heads, knocked Hatley into the ropes with a hard right at the end of the round and flattened the challenger once before the knockout blow.
Hatley, who saw a nine-fight win streak snapped, had not fought for 17 months, since knocking out Australian ex-champ Anthony Mundine in November 2015.
The fight was on the undercard of an all-US welterweight matchup at Barclays Center between former champions Shawn Porter and Andre Berto.