Mexican great Saul ‘Canelo’ Alvarez further added to his legacy by taking the WBO light-heavyweight crown from Sergey Kovalev with a devastating 11th-round knockout in Las Vegas.
Middleweight king Canelo, 29, had stepped up two weight divisions to face the 36-year-old Russian.
It proved a close fight which failed to ignite before an explosive combination from Canelo ended Kovalev’s night.
Canelo has now won world titles in four weight divisions.
A cagey encounter at the MGM Grand appeared to be heading to a 12th round and one for the judges to decide before a left hook-right hand combination came from nowhere and left Kovalev floundering on the ropes.
Judges had Canelo slightly ahead at that point on their scorecards.
Canelo, the best-paid fighter in the sport, said winning a title at a fourth weight was an attempt to further enhance his reputation in his boxing-obsessed homeland.
He started his career at 139lbs when he boxed as a 15-year-old on debut in 2005 and had won world titles at light-middleweight, middleweight and super-middleweight before this latest victory.
Kovalev was a tough opponent in what was his 16th consecutive world title fight, a run which started when he dismantled Briton Nathan Cleverly in Cardiff in 2013.
But the victory means Canelo still has just one defeat in 56 fights – against Floyd Mayweather in 2013.