Officials felt Angel Acosta simply lost too much blood to continue in his WBO flyweight title fight Friday night.

Referee Rocky Burke stopped his championship bout against defending champion Junto Nakatani because he determined that Acosta’s badly bloodied nose had become too dangerous early in the fourth round. Japan’s Nakatani retained his title, improved to 22-0 and recorded his 17th knockout on the Oscar Valdez-Robson Conceicao undercard at Casino Del Sol’s AVA Amphitheater in Tucson, Arizona.

Puerto Rico’s Acosta (22-3, 21 KOs) was officially stopped 32 seconds into the fourth round of a scheduled 12-round, 112-pound championship match.

There wasn’t much action in the fourth round before Burke halted the action.

Burke called for the second break in as many rounds with 1:22 on the clock in the third round, so that a ringside doctor could examine Acosta’s bloodied nose.

Acosta’s nose continued to bleed badly once the action resumed. He tried to protect himself better and tied up Nakatani at times before the third round concluded.

A ringside physician took an extended look at Acosta’s bloodied nose with 1:13 to go in the second round. Acosta, whose nose began bleeding during the first round, opted to continue.

He came forward and threw hard shots for the remainder of the second round. Acosta’s left hook backed up Nakatani with just over 10 seconds to go in that second round.

Nakatani landed a left hand just before the halfway point of the opening round. His left to the body knocked Acosta off balance with just over a minute remaining in the first round.

A right hook by Nakatani wobbled Acosta with just under 40 seconds to go in the first round. It was obvious by then that Nakatani had the heavier hands.

Keith Idec is a senior writer/columnist for He can be reached on Twitter @Idecboxing.