Terence Crawford won his fourth world title at different weights by beating Israil Madrimov to claim the WBA light-middleweight crown in Los Angeles.
The 36-year-old American won by unanimous decision at the BMO Stadium to extend his unbeaten record to 41 fights.
A former lightweight world champion who was also undisputed champion at light-welterweight and welterweight, Crawford triumphed 116-112, 115-113 and 115-113 on the judges' scorecards.
Defeat was the first of 29-year-old Uzbek Madrimov's 11-bout career.
"Israil was a tough competitor," said Crawford, who had not been taken to 12 rounds since 2016.
"He's real strong. He's durable. He took a lot of good shots. He got me to round 12.
"He had fast speed, a good rhythm upstairs. He was very disciplined and he fought a good fight.
"I was being patient. I didn't want to rush in with anything. That's how I got caught a couple times - I tried to eat too soon."
Crawford's win opened up the possibility of a fight with Mexico's super-middleweight champion Canelo Alvarez.
"If the money is right, we've got to fight," said Crawford.
BBC