SAN ANTONIO, Texas - Nonito Donaire knocked down Wilfredo Vazquez Jr in the ninth round en route to a split decision over the former champ in a super bantamweight title bout in San Antonio, Texas.

Donaire, a former International Boxing Federation flyweight and World Boxing Council bantamweight title holder, claimed the World Boxing Organization belt in his first foray at super bantamweight.

The 12-round bout was on the undercard of the World Boxing Council middleweight title fight between unbeaten champion Julio Cesar Chavez Jr. and Marco Antonio Rubio at the Alamodome.

Donaire, of the Philippines, brought plenty of his power with him into the heavier weight class, dropping Vazquez in the ninth with a left uppercut followed by a left hook.

Donaire had rocked Vazquez in the third round and appeared in control until the Puerto Rican began to assert himself in the fifth and sixth rounds.

Despite the tenacity of Vazquez, Donaire said he was surprised that judge Ruben Garcia scored the bout 115-112 for the Puerto Rican.

Judges Levi Martinez and Don Trella both saw it 117-110 for Donaire, who said he hurt his left hand early in the bout and displayed what appeared to be a bloodied hand wrap when he removed his gloves after the fight.

Donaire said fighting a bigger opponent “was tougher than I expected.”

“I couldn't find my rhythm and I hurt my hand somewhere between the second and fourth rounds,” he said. “I could only move it a little bit.”

Donaire, who also once held the World Boxing Association interim super flyweight championship but not the official crown, improved to 28-1 with 18 knockouts.

Vazquez fell to 21-2-1 with 17 wins inside the distance.

Their fight was for the WBO belt Vazquez lost to Jorge Arce, who then vacated it to fight for the bantamweight belt Donaire relinquished when he moved up in weight.