[3][4] He was one of the first three Asian fighters with world titles in at least four weight classes alongside fellow Filipinos Manny Pacquiao and Nonito Donaire.

On, May 22, 2004, he won the Philippines Boxing Federation (PBF) light flyweight title against Joseph Villasis via first-round technical knockout.

On November 24, 2006, Nietes won the vacant WBO Asia Pacific Minimumweight Title against Heri Amol of Indonesia via second-round knockout.

In the 10th and final round, Nietes was declared winner by TKO when Silvestre stopped to take a drink of water during the fight, a move that was against the rules.

[12] On October 8, 2011, Nietes defeated Mexico's Ramón García Hirales via 12-round unanimous decision to win the WBO Light Flyweight title.

[13] On November 15, 2014, the Bacolod native successfully defended his WBO and The Ring Light Flyweight titles by stopping Carlos Velarde of Mexico in the 7th round.

[14] Nietes became the longest-reigning Filipino world champion on that same day, surpassing the record previously held by Gabriel Elorde.

[15] After breaking Elorde's record, Nietes successfully defended his title four more times before deciding to move up to the flyweight division.

[16] On April 29, 2017, Nietes became the third Filipino boxer to win world titles in three different weight divisions, along with Manny Pacquiao and Nonito Donaire when he defeated Thailand's Komgrich Nantapech.

[20] Nietes made his debut in the junior-bantamweight division against Filipino compatriot Aston Palicte for the vacant WBO Super Flyweight Championship.

[22][23] While not beaten, Nietes was denied a victory that would have put him alongside Manny Pacquiao and Nonito Donaire as the only Asian fighters with world titles in at least four weight classes.

[25] On February 28, 2019, Nietes decided to vacate his WBO Junior Bantamweight title to pursue more lucrative fights in a different organization or weight class.

[27] On December 11, 2021, Nietes made his first title defense against Norbelto Jimenez at the Coca-Cola Arena, Dubai, United Arab Emirates.

[31] Nietes is set to face Muhammad Waseem on July 22, 2023, in Dubai for the vacant IBO bantamweight world title.