Miguel Cotto won the WBO light welterweight crown on Saturday with a sixth-round knockout of Kelson Pinto.
Cotto attacked from the opening bell to claim the vacant belt and win his first title fight in his native Puerto Rico.
The fight was stopped 32 seconds into the sixth round after a series of combinations sent the Brazilian to the canvas for the second time.
Pinto beat the count but was visibly hurt and the referee called a halt after Pinto's corner entered the ring.
"He came out strong, but we imposed our plan," said
Cotto, who improves to 21-0 with 17 KOs.
It was the first loss in 21 fights for Pinto, who had defeated Cotto twice as an amateur.
On the same card, Daniel Santos retained his WBO light middleweight champion with a split technical decision over Antonio Margarito.
Margarito was cut over the right eye by an unintentional headbutt in round six and after round nine it was ruled Margarito could not continue.
The bout went to the cards and Santos was up 86-85, 87-84 on two cards while Margarito was ahead 86-85 on the third.
Meanwhile, Hungary's Zsolt Erdei defended his WBO light heavyweight crown with a unanimous decision over Alejandro Lakatus in Budapest.
It was the second successfull title defense for Erdei who remains undefeated at 21-0 with 13 KOs.
And in Thailand, Veeraphol Sahaprom retained his WBC bantamweight title with a unanimous decision over Mexico's Cecilio Santos.
It was the 36-year-old's 14th defence of the title he won back in 1998.