KELL BROOK was leading the fight against Terence Crawford before the brutal round four finish.
The judges ringside scorecards in Las Vegas revealed two had Brook ahead after three rounds.
They scored Brook taking the first two sessions but conceding the third.
The other judge awarded the 34-year-old Brit the opening stanza but had Crawford taking the following two.
In the end it mattered little, as Brook’s early success was canceled out as he was finished on his feet.
Crawford, 33, landed a perfectly timed right hand in the southpaw stance which spelled the beginning of the end.
Brook was sent reeling backwards and took punishment on the ropes before a standing eight-count was called.
He was given the chance to fight on but was still dazed as Crawford – who came into the fight with a 75 per cent finish rate – sensed blood.
The Nebraskan landed another right hook over the top and after a string of left hands, Brook was saved by the referee Tony Weeks.
It is Brooks’s third loss, following defeats to Gennady Golovkin at middleweight in 2016 and to Errol Spence Jr when he lost his IBF welterweight belt a year later.
After the stoppage, he admitted: “Never in my career, nobody has ever done that to me in sparring or anything.
“It was one of them… I got caught with a shot I didn’t see. I’m gutted because nobody could’ve gotten me in better condition.
“I was bang on the limit. Maybe I could’ve been a bit more relaxed and loose and let the shots go.”
Crawford said: “I was trying to gauge the distance. He had good distance.
“I was trying to find my rhythm in between getting my distance together. That’s why it was so competitive at first. I couldn’t get my shots off.
“Kell is a tremendous talent. He came and he tried to take my title. He was in shape.
“He made the weight. There were no excuses to be put on the table. He came off of three wins.
“He lost to the better man.”
