By Francisco Salazar

Junior featherweight contender Emanuel Navarrete has come a long way from his only defeat as a pro at the age of 17. Almost six years later, he is now a mandatory challenger to a world title belt.

Navarrete slowly broke down Jose San Martin, dropping him twice in the later rounds to win by knockout in the 12 round at the Arena Jose Sulaiman in Monterrey, Nuevo Leon, Mexico.

With the win, Navarrete wins an interim title belt and becomes the mandatory challenger for the winner between WBA titleholder Danny Roman and Moises Flores on June 16.

The victory did not come easy for Navarrete (25-1, 22 knockouts), a Mexico City resident and one of the top young fighters that is promoted by Zanfer Promotions.

The taller Navarrete was effective fighting from distance, mixing his attack to the head and body. Navarrete would throw wide hooks and crosses, prompting San Martin, who resides in Barranquilla, Colombia, to counter with straight right hands to the head of Navarrete.

Navarrete mostly controlled the first half of the fight, but San Martin was effective in spots in rounds seven and eight. Navarrete did well in round 10, and it seemed momentum was creeping in favor of San Martin.

The tide turned early in round 11, when a barrage of punches stunned San Martin. Navarrete pressed the action, throwing and landing at will, wearing down San Martin. The tactic worked later in the round, as Navarrete trapped San Martin in a corner, landing a barrage of punches that forced San Martin to take a knee.

San Martin was able to survive the round.

Navarrete instinctually went on the attack when the bell sounded to open the 12th round. A barrage of punches forced San Martin to take a knee again, prompting referee Rafael Ramos to count San Martin out.

In the co-feature bout, junior flyweight Daniel Valledares won a close 10 round unanimous decision over previously-unbeaten Adrian Curiel.

It was a decent tactical fight between two prospects that fight under the Zanfer Promotions stable. The fight was marred at times by numerous accidental clash of heads between the two fighters.

A clash of heads in round three opened a severe cut above the right eye of Valladares. Because a minor WBC belt was on the line, per its putrid bylaws, referee Sergio Hernandez deducted a point from Curiel.

During the middle rounds, Curiel was the more effective fighter, beating Valladares to the punch during exchanges. It was Valladares who landed the more telling blows during the final two rounds, which likely won him the fight.

Scores were 95-94, 95-94, and 98-91 in favor of Valladares, who resides in the Monterrey area.

Curiel, a Mexico City resident, drops to 10-1, 3 KOs.

Francisco A. Salazar has written for Boxingscene.com since September of 2012 and has covered boxing in Southern California and abroad since 2000. Francisco also covers boxing for the Ventura County (Calif.) Star newspaper. He can be reached by email at santio89@yahoo.com or on Twitter at FSalazarBoxing