The Scotsman’s world title reign, which stretched back to May 2019, came to an end as Taylor struggled to cope with the blurring fists and slick movement of Lopez, who took command in the second half of the bout to seal victory with scores of 115-113, 115-115 and 117-111.
Taylor, returning to the ring for the first time since a contentious win over Jack Catterall in February 2022, had made an impressive start to the fight in Madison Square Garden.
Using his size and reach advantage, the 32-year-old southpaw produced some accurate jabs and crunching body shots in the early rounds.
Lopez slipped to the canvas in the third, but then pushed Taylor to the floor in the fourth before staggering the Scot in the final seconds of the round with a powerful shot.
Taylor fired back in the next round with a crisp combination, although Lopez cranked up the aggression in the sixth, slipping one punch below the belt line as he regained command.
Lopez oozed confidence in the seventh, but had to absorb a couple of clean shots from Taylor before he rocked him with a right hand at the end of the round.