Kiyoshi Ueda, 55, a former House of Representatives member, won the Saitama gubernatorial election Sunday, early returns show.
Ueda will fill the post vacated by Yoshihiko Tsuchiya, who resigned in July over a political funds scandal involving his daughter.
Ueda gave up his Diet seat and resigned as vice secretary general of the Democratic Party of Japan, the largest opposition force, to run as an independent. He defeated seven other candidates in the closely watched race.