Kazumi Ota of the Democratic Party of Japan won Sunday's by-election in Chiba Prefecture, overcoming the party's e-mail fiasco in the Diet and giving a shot in the arm to the leadership of Ichiro Ozawa, its new president.

Ota, 26, a former member of the Chiba Prefectural Assembly, beat Ken Saito, 46, of the ruling Liberal Democratic Party and former vice governor of Saitama Prefecture, to replace an LDP lawmaker forced to resign over a campaign scandal.

Also running in the Chiba No. 7 district were Kiyoko Tokumasu, 53, of the Japanese Communist Party and two other candidates.