CALLUM Smith ended fellow Briton George Groves’ 16 month reign as WBA world super-middleweight champion and won the World Boxing Super Series with a stunning seventh-round knockout.
The Liverpudlian, 28, landed a left hook which rocked Groves backwards, and unleashed a flurry of further punches before a body shot finally floored his opponent.
As 30 year-old Groves shook his head and failed to beat the count, Smith dropped to his knees in celebration.
Smith follows his sibling Liam in becoming a world champion and achieved the feat in the unusual surroundings of Jeddah, Saudi Arabia.
All four Smith brothers, including former British champions Paul and Stephen, embraced in the ring after the fight.
Callum, the youngest of the four, entered the inaugural World Boxing Super Series to give himself a chance of winning a world title, as the more traditional routes had not opened for him.
As the taller fighter, Smith kept enough distance to force Groves into committing forward, while being close enough to counter with well-timed right hands.
Smith picks up the biggest share of the €6.9 million prize money, and is now likely to target a title defence in his home city of Liverpool, before turning to potential unification fights.