Farenas made his professional debut on September 19, 2004 against Octavio Olinar at the Sports and Cultural Complex in Mandaue, Philippines.

On March 15, 2008, Farenas challenged Mexican boxer Baudel Cardenas in the undercard of the Manny Pacquiao-Juan Manuel Marquez big fight at the Mandalay Bay Resort and Casino in Paradise, Nevada.

For the fight, the protégé of former WBO bantamweight champion Gerry Peñalosa trained under the guidance of Freddie Roach.

[2] Farenas won the World Professional Boxing Federation featherweight title on October 3, 2009 by stopping South Korean fighter Jae-Bong Jang in 9 rounds.

The bout ended in a no contest after 2 round, because of an accidental clash of heads that opened a bad cut over Morales' right eye.

[3][4] In his next bout, Farenas challenged Marlon "Rata" Aguilar of Nicaragua in the undercard of the Latin Fury 14 pay-per-view, which showcased the return of Antonio Margarito against Roberto Garcia in Aguascalientes, Mexico.

Farenas lost by an eight-round unanimous decision and practically blew away his chance at a possible world title bout.