Liam Smith will face his toughest test to date when he defends his WBO light-middleweight title against former two-weight world champion Saul 'Canelo' Alvarez on September 17 in the United States.

Smith (23-0-1, 13KO wins) has made two routine defences since capturing the vacant crown with a seventh-round stoppage of John Thompson in October last year and will be facing a serious step up in competition.

Alvarez has won 47 of his 49 professional contests, with his only loss coming against former pound-for-pound superstar Floyd Mayweather three years ago, and most recently brutally knocked out Smith's British compatriot Amir Khan.

Smith was one of Khan's sparring partners for the bout and has now been given the opportunity to succeed where Khan failed against the Mexican sensation.

He said: "I am delighted to get the opportunity to defend my world championship again, this time against the biggest name in world boxing, Canelo Alvarez, and headline in America which is a dream I have had since I started in boxing.

"This fight will allow me to make a name for myself in the US and show the Americans and Mexicans just how good I am. As soon as I became world champion my next goal was to make my name across the Atlantic and this is the big stage that will enable me to do that.

"My trainer Joe Gallagher and I are going to initiate a plan to ensure we beat Canelo and shake up the world of boxing. I am confident of keeping my title on September 17 and returning to Liverpool with my belt still around my waist."

No venue has yet been announced for the encounter.

Smith's promoter Frank Warren said: "Liam grabbed the opportunity to take on Alvarez. This is a fantastic chance for Liam to showcase his talent in such a high-profile fight and in America. He believes, as do I, that he has the tools to beat Alvarez and stake his own claim to be the world's best."

Alvarez (47-1-1, 33KO wins), a former WBC and WBA champion at the 154lb limit, made the first defence of his WBC middleweight crown by stopping Khan.

It had been anticipated he would face off against WBA and IBF champion Gennady Golovkin but Alvarez opted to vacate the belt, which has since been awarded to the Kazakh.

Alvarez, 25, said: "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 on September 17