Callum Smith claimed the WBA super-middleweight title in emphatic fashion, dethroning George Groves thanks to a seventh-round stoppage in the World Boxing Super Series final.
Challenger Smith followed older brother Liam - who held the WBO strap at light-middleweight - in becoming a world champion, reeling off a 25th successive victory as a pro.
Groves, who had recovered from a dislocated shoulder suffered in the final round of his February points victory over Chris Eubank Jr in time to defend his belt in Jeddah, struggled against his taller opponent from the outset.
Saint George looked to be in need of divine help as early as the third round after being caught by a right hand from Smith, though he survived the ensuing onslaught.
The 30-year-old Londoner looked to be finally finding his rhythm in the fifth, suggesting he was warming to the task at hand inside the King Abdullah Sports City Arena.
However, his growing confidence would lead to his downfall, as a desire to land a looping right hand created the opportunity for Smith to counter with a crunching left hook.
The blow sent Groves stumbling backwards and, after coming in for some heavy punishment while stuck in a corner, he eventually dropped to the floor.
With his rival failing to beat the count, Liverpudlian Smith was able to celebrate the biggest win of his career to date.
As well as securing a coveted world title, 'Mundo' also received the Muhammad Ali Trophy as champion of the first series of the eight-man competition at the weight limit.