Watanabe won the opening round at Motegi then rode consistently throughout the season, handing him a 21 point lead over Moriwaki Honda's Tatsuya Yamaguchi heading into the season finale.
Yamaguchi fell on the opening lap of the first race, in which Watanabe finished sixth, putting him 19-points clear of new second-placed rider Takashi Yasuda, of Harc Pro Honda, going into the final race. Watanabe took ninth in the finale, enough to secure his second title - the first being in 2002 - and the first for the Yoshimura team since Doug Polen in 1989.
Both Suzuka races were won by reigning double BSB champion Ryuichi Kiyonari - and, while Kiyonari will head to WSBK in 2008, Watanabe looks set for BSB, with Rizla Suzuki.
"I would like to say thank you for all my fans and my team staff. I've been with Yoshimura for five years and I'm very happy to win the title for them and hope to graduate from the Japanese Championship to a foreign series next year," Watanabe confirmed.
Rizla Suzuki is looking for two new riders for 2008, after the departure of both Chris Walker and Cal Crutchlow.
