Josh Taylor suffered his first defeat and lost his WBO and Ring Magazine super-lightweight titles to Teofimo Lopez on points in New York.
It was the 32-year-old Scotsman's first bout since his contentious win over Englishman Jack Catterall in February, 2022 and it was another struggle at The Theater at Madison Square Garden.
The Scot started well enough but Lopez grew in confidence and finished the fight strongly, landing some thumping shots, particularly in the second-half of the bout, which impressed the judges who declared a unanimous win for the 25-year-old Brooklyn boxer.
Steve Gray called it 115-113 as did Joe Pasquale with Benoit Roussel scoring it 117-111 for the new champion.
Afterwards Taylor, whose first loss came in his 20th fight, was magnanimous in defeat, telling Sky Sports: "No excuses. He was better on the night. It is what it is so congratulations to Teofimo.
"I would love to do it again. I know I am better than that and I know I can beat him.
"So yes, I would love to do it again but he’s the champ and the ball is in his court."
Lopez said: "It has been a long time coming.
"We just beat the No 1 champion, Josh Taylor, former undisputed champion."
Taylor, who unified the division before vacating several titles, had started impressively.
Using his size and reach advantage, Taylor's southpaw delivered some accurate jabs and powerful body shots in the early rounds.
Lopez slipped to the canvas in the third and pushed Taylor to the ground in the fourth where he staggered the Scot in the final seconds of the round with a powerful shot.
Taylor came back in the next round with a clean left and right before Lopez landed a low blow in the sixth where he again finished the aggressor.
Lopez looked confident coming out for the seventh but had to absorb a couple of clean shots from the Scot before he rocked him with a right hand at the end of the round.
The home fighter indulged in some showboating in the eighth round as his confidence increased further.
Lopez's hand speed was causing all sorts of problems for Taylor who was rocked again in the ninth round which the challenger dominated.
Taylor was clipped twice in the 11th round which ended with Lopez lifting his arms in a victory pose which the Scot replicated but less convincingly.
In the final round Taylor was again left unsteady on his feet after taking some shots with Lopez clearly believing he had won when the bell rang – the judges confirming that belief moments later.
