In January 2019 Martínez announced his decision to go pro by signing a deal with Latin ARMS Promotions and former referee Richard Steele as his manager.

[32][33] He trained with the legendary Ignacio Beristáin in Mexico, and his first opponent was announced to be 46-year-old Nicaraguan former world champion Ricardo Mayorga, who stated in an interview that he would retire if he lost to the 23-year-old.

[34] On 6 April 2019 he defeated Mayorga by technical knockout (TKO) in the main event of a card in Guatemala City, backing the ex-champ into the ropes with power shots until the referee waved it off in the final second of the second round.

[35][36] Two months later faced Daniel Montejo in Tijuana, scoring three knockdowns en route to a first-round knockout (KO) victory.

[38] He made his return on 27 August 2020, stopping Mexican rival Abraham Hernández in the second round of their Roy Jones Jr.-promoted fight in Guaymas.