[2] Martínez had his first step-up fight on 16 December 2019, as he was scheduled to challenge the reigning WBC Silver super flyweight champion Athenkosi Dumezweni.

[4] Martínez next faced Angel Nicolas Aquino on 11 December 2020, at the Estadio Mary Terán de Weiss in Buenos Aires, Argentina.

The title fight was scheduled for the undercard of the Chris Colbert and Hector Garcia WBA super featherweight bout, which took place at the Cosmopolitan in Las Vegas, Nevada.

As such, Martínez was booked to face Jerwin Ancajas in an immediate rematch in his first championship defense, which took place on 8 October 2022,[12] at the Home Depot Center in Carson, California.

[21] Martínez beat the WBA flyweight champion Kazuto Ioka by unanimous decision in a title unification bout on 7 July 2024.