RIO DE JANEIRO - Anderson Silva beat Yushin Okami by knockout with two minutes four seconds left in the second round, winning his 15th straight fight and successfully defending his middleweight title at UFC 134 on Saturday night.
Silva sent Okami to the ground with a right-handed shot to the jaw, then pounded him with strikes to the head to force the fight to be stopped.
The 36-year-old Brazilian, touted as the MMA's best pound-for-pound fighter, improved to 29-4 (14-0 in UFC), while Okami fell to 27-6 (10-3).
Silva's last loss had been against Okami in 2006, when the Brazilian dominated the bout but was disqualified after an illegal kick.
Silva has defended his title a record nine times and is the longest-reigning champion in UFC history.
"I'm so happy," Silva said. "I've trained so hard for this."
The Ultimate Fighting Championship is making a much-anticipated return to Brazil, the country where mixed martial arts came to life in the early 1990s. There hadn't been a UFC event in Brazil since 1998, when the sport was not nearly as popular as it is now.
Silva, a striker known as "The Spider," struggled to get to Okami in the first of the five-round fight, but he came out attacking in the second and dominated.
He struck a right-handed shot with 4:17 left to send Okami to the ground for the first time. The Japanese fighter recovered, but not after the second charge by Silva in front of more than 15,000 fans who packed the HSBC Arena in Rio de Janeiro.
The 30-year-old Okami had won six of his last seven fights.
Brazilians won four of the five fights on the main card.
In the light heavyweight division, Brazilian Mauricio (Shogun) Rua knocked out American Forrest Griffin in the first round with a series of strikes to the head. Rua had lost to Griffin in his UFC debut in 2007, and the crowd celebrated the victory by chanting, "Shogun is back, Shogun is back."
In the heavyweights, home-crowd favourite Minotauro Nogueira defeated American Brendan Schaub by knockout despite not having fought in 18 months because of a series of injuries, giving Brazil its first win of the night in the main card. The emotional victory gave the 35-year-old Nogueira a 37-6-1 record.
Bulgaria's Stanislav Nedkov made his UFC debut by defeating Brazil's Luiz Cane by knockout in a light heavyweight fight to improve his record to 12-0, while Brazil's Edson Barboza reached 9-0 by beating England's Ross Pearson with a split decision in the lightweight division.
Montreal bantamweight Yves Jabouin defeated Ian Loveland by split decision in the undercard.
Some of the celebrities at the event Saturday included retired soccer star Ronaldo, whose sports marketing agency manages Silva's career.
The fans constantly chanted during the fights, and even some soccer-stadium songs made their way into the fights.
UFC President Dana White has already said he plans to return to Brazil soon and increase the number of events in the country of 190 million people. There is even talk of a possible fight at a soccer stadium, which could attract a crowd of nearly 100,000 fans.