Nonito Donaire stopped Jorge Arce with a left hook late in the third round Saturday night to retain the WBO super-bantamweight title and send the Mexican veteran into retirement.
Donaire, from the Philippines, improved to 31-1 with his 20th knockout. Arce dropped to 61-7-2.
"My left hook was a damaging hook tonight," Donaire said. "I felt very strong in the ring."
Donaire won in front of a raucous, mostly pro-Arce crowd of 7,250 at Toyota Center.
"The reason why people survive is because they are afraid to open up," Donaire said. "I have a lot of respect for (Arce) because he came in there and he opened up. He wasn't afraid. He was aiming to surprise me. But when he was opening up, that gave me the left hook and when I can throw sitting down on that left hook, everybody will go down."
The 30-year-old Donaire hasn't lost a fight in more than 11 years. He also knocked down Arce with about 2 minutes to go in the second round with a right-left combination.
"I'd promised my kids that If I lost this fight, I'd retire," said the 33-year-old Arce, a former world champion. "Fortunately, I have taken care of what I have earned through the years."
The fight headlined HBO's "World Championship Boxing" season finale, and the broadcast marked Larry Merchant's last after 35 years as a ringside boxing commentator for the network.
"All good things come to an end," Merchant told The Associated Press prior to the fight. "There will always be more fights. It was great to go out on a great fight like last week (Juan Manuel Marquez's knockout of Manny Pacquiao) and to be able to speak directly to all the fans of HBO Boxing for all these years."
The 81-year-old Merchant was inducted into the International Boxing Hall of Fame in 2009.
"Thirty-five years on one show in television? I never imagined that it could go on for that long, because that is not what happens in the entertainment world."
An undercard fight between WBA super-bantamweight champion Guillermo Rigondeaux of Cuba and Poonsawat Kratingdaenggym of Thailand was scratched after Poonsawat failed a physical this week.
Poonsawat was denied a license by the Texas Department of Licensing and Regulation after he failed blood tests. The reason for the failed blood tests wasn't disclosed.