Toronto, Canada – A hard right-left combination from the challenger knocked Luevano down and although the American made it to his feet referee Benjy Esteves stopped the contest.
"It was a tough fight. He's an intelligent fighter," said Lopez, a former WBO super-bantamweight champion making his first appearance at featherweight. "It wasn't one of the toughest, but it was a little uncomfortable, because he is difficult."
The fight began cautiously with Luevano (37-2-1) trying to dictate with his jab but Lopez (28-0) took charge from the third, landing a series of jarring left hands.
Luevano rallied in the fifth, fighting well on the inside, but southpaw Lopez regained control in the sixth, cutting his opponent under the left eye and bloodying his nose.
(Writing by Kieran Mulvaney in Washington, D.C; Edited by Patrick Johnston)