After leaving WCW, he returned to CMLL and began wrestling for CMLL's Japanese affiliate, New Japan Pro Wrestling (NJPW). In 2001, he adopted the Black Tiger character, previously used by Mark Rocco and Eddie Guerrero, making him the third person to appear under the mask, which is why he's unofficially referred to as Black Tiger III in printed sources. As Black Tiger, he wrestled several tours with New Japan starting out working a series of matches with the storyline opponent of the Black Tiger, Tiger Mask – in this case, Tiger Mask IV. Together with his brother Dr. Wagner Jr., he had an unsuccessful IWGP Junior Heavyweight Tag Team Championship challenge against the team of Jushin Thunder Liger and El Samurai in 2001.