WASHINGTON -- Argentina's Fernando Martinez retained his IBF world junior bantamweight title on Saturday with an 11th-round stoppage of Filipino challenger Jade Bornea in a battle of unbeatens at Minneapolis, Minnesota.

Referee Charlie Fitch stopped the bout 29 seconds into the 11th round after Martinez opened a bloody gash on the right ear of Bornea early in the ninth.

"I definitely saw the injury in the ear," Martinez said through a translator. "I hit it with a left and it popped, it exploded. I just kept going at the ear and that's what ended this fight."

Martinez improved to 16-0 with his ninth victory inside the distance while Bornea fell to 18-1 after dropping his first world title bout.

"The training camp we had was brutal. It was great," Martinez said. "The stronger fighter won and it was me."

It was the South American's second defense of the 115-pound division crown he captured 16 months ago from Philippines fighter Jerwin Ancajas and kept in a rematch last October, both wins by unanimous decision.

Bornea, 28, went to a southpaw stance at the start against Martinez as they traded combinations going toe to toe in the early rounds.

Martinez, 31, landed a hard left in the fifth round but a clash of heads denied him a chance to press the advantage.

Early in the ninth round, a left hook by Martinez exploded Bornea's right earlobe. Blood splattered and gushed down Bornea's neck but he made it through the round and told Fitch he wanted to continue.

Martinez landed a flurry at the end of the 10th round and attacked Bornea's face early in the 11th before Fitch halted the contest.

© Agence France-Presse