With plans for a fight between Canelo Alvarez and Gennady Golovkin put on hold earlier this week, Alvarez, the lineal middleweight champion, will instead drop down a weight class to fight junior middleweight champ Liam Smith for Smith's crown in a bout scheduled on Sept. 17, it was announced Friday.
A site for the fight has not yet been determined, but it will be televised by HBO on a pay-per-view basis.
A more attractive fight between Canelo and Golovkin has been postponed until the fall of 2017, and Canelo will be favored to add the 154-pound title to his 160-pound crown when he fights Smith.
"I am very pleased to announce my next fight against Liam Smith, a tremendous fighter with real knockout power, and the WBO junior middleweight world title owner," said Alvarez (47-1-1, 33 KOs). "I have no doubt that this fight will be give and take, which will fill the expectations of the fans, and I will work with all the enthusiasm as I always do to get the upper hand."
He beat Miguel Cotto in November to win the middleweight crown and defended it with a knockout of Amir Khan in May.
The 27-year-old Smith is undefeated, but he is not well known to American fight fans. The British fighter won the 154-pound title with a knockout of John Thompson in October and defended it twice.
"I am delighted to get the opportunity to defend my world title against the biggest name in world boxing and to headline in the U.S. which is a dream I have had since I started in the sport of boxing," said Smith (23-0-1, 13 KOs). "This fight allows me to make my name in the U.S. and show just how good I am and this is the big stage that will enable me to do that.
"I am confident of winning this fight and returning to the great city of Liverpool with my belt still around my waist."