Great Britain's Liam Smith lost his WBO light-middleweight title to Mexican Saul 'Canelo' Alvarez in Dallas.
Alvarez, 26, won with a ninth-round knockout as Smith, who had also been floored in the seventh, failed to beat the count following a body punch.
It was 28-year-old Smith's first defeat in 25 fights, in the third defence of the title he won in October 2015.
After the fight, Alvarez said "we are ready" for WBC, WBA and IBF middleweight champion Gennady Golovkin.
"He doesn't want to accept," said Alvarez. "I fear no man. I am the best at this sport. I want to fight the best.
"About a month ago, we offered 'GGG' three or four times as much to make the fight."
Alvarez has lost only one of his 50 professional fights, against American Floyd Mayweather on points in 2013.
Kazakh Golovkin, 34, beat Britain's Kell Brook in London last week to extend his unbeaten record to 36 fights, icluding 33 knockouts.
Smith said: "I am very disappointed. Canelo was too good. My timing was off."