The 27-year-old, who is a three-time European champion, stopped dangerous South African Jeffrey Mathebula in the ninth round of their contest after dominating most of the proceedings in Elche.
Mathebula, 34, had only previously been stopped once before, and that was very early on in his career, although Martinez was able to get him out of there late to score his 22nd career stoppage.
Rumors are now rife that ‘La Sensacion’ could be set for a rematch with old foe Carl ‘The Jackal’ Frampton after the Belfast man demolished him in the same number of rounds the last time they met in February.
To my mind, those talks may be rather premature as it is questionable whether Martinez would want to put the title up he worked so hard for against a fighter who beat him so convincingly in the past.
In the night, French cruiserweight Youri Kalenga, who Gary Hyde manages, took his pro record to 18-1 with a second consecutive early finish.
