via heel hook. Fighting Network RINGS After his switch to MMA in Fighting Network RINGS, he submitted a striker in the form of Andre Mannaart, and was pitted against sambo and kickboxing expert Valentijn Overeem in his next shoot match. Outweighed by 25 lbs, Tamura managed to take Overeem down early in the fight and fought for a kimura, however Overeem submitted Tamura multiple times, the Japanese ultimately losing the match by kneebar. It forced the RING executives to make him lose the Openweight Championship to Tariel Bitsadze. He then had an acclaimed draw against teammate Tsuyoshi Kohsaka. In 1999, Tamura faced former Pancrase star Frank Shamrock, who had defeated Tamura's teammate Tsuyoshi Kohsaka years before and become his training partner in The Alliance. Tamura controlled the match, taking down Shamrock and keeping dominant position over him, but he was forced to spend a rope escape when Shamrock caught him in an armbar in his first takedown. The Japanese retaliated by threatening him with a Kimura lock, another armbar and a pair of scarf hold armlocks which almost finished the fight, but the American miraculously escaped from all of them. After twelve minutes, however, Shamrock lost the point for an illegal closed-fisted punch, balancing their respective point scores and forcing him to switch to attack. Shamrock attempted a Kimura lock and an ankle hold, but Tamura defended them successfully and the time of the match ran out. It was declared a draw by points. The same year, Tamura took part in the King of Kings tournament, facing Dave Menne as his first opponent. He landed several hooks, but lost the advantage upon attempting a flying armbar. After the restart, they exchanged strikes until Menne slipped down on a high kick, which Tamura capitalized in order to mount Menne on the ground and throw punches. Finally, Tamura knocked down Dave again and took his back, ending the match with a unanimous decision. Following an uneventful second round win over Borislav Jeliazkov, Tamura found himself pitted against Renzo Gracie from the Gracie family. The Brazilian fighter got the earliest of the fight with a guillotine choke from the guard, but Tamura started to dominate thanks to his superior striking and takedown defense. Believing himself to be the superior on the ground, Renzo lied down and challenged Tamura to grapple with him, which the Japanese shooter did, managing to pass his guard and