By Keith Idec

NEW YORK – His win was unconventional, but Christopher Diaz continued his move toward a 130-pound title shot Saturday night.

The unbeaten super featherweight contender from Puerto Rico beat Braulio Rodriguez by fourth-round technical knockout after Rodriguez suffered a hand injury and couldn’t continue. Diaz (23-0, 15 KOs) and the Dominican Republic’s Rodriguez (19-3, 17 KOs) were exchanging near a neutral corner early in the fourth round, when Rodriguez started shaking his right glove and bent over.

A New York State Athletic Commission physician determined Rodriguez couldn’t continue in their scheduled 10-rounder on the Amir Imam-Jose Ramirez undercard. The 23-year-old Diaz, who retained his NABO super featherweight title, was declared the winner by technical knockout 28 seconds into the fourth round.

Rodriguez, 29, had not lost by knockout or technical knockout before Saturday night and had knocked out 17 of his first 21 professional opponents.

Rodriguez connected with a combination in the center of the ring that made Diaz cover up early in the third round. Referee Gary Rosato warned Rodriguez for using his extended left arm to fend off Diaz later in the third.

Rodriguez landed two hard right hands toward the end of the third. Diaz fired back with a left hook, but Rodriguez shook his head to signify that it didn’t hurt.

Diaz, mindful of Rodriguez’s power, tried to use angles to attack Rodriguez during the second round, but didn’t land anything impactful.

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