SAITAMA (Kyodo) Hayato Shimizu, supported by the Democratic Party of Japan, was headed toward certain victory in Sunday's mayoral election in the city of Saitama, beating five rivals, including the incumbent backed by the ruling camp, according to Kyodo News projections.

The election has been closely watched as the first major local election since Yukio Hatoyama took over as DPJ president earlier this month from Ichiro Ozawa, who resigned over a fundraising scandal involving his top aide.

A win by Shimizu would provide the DPJ with a boost heading into the general election that must be held before October and deal a blow to Prime Minister Taro Aso, whose Cabinet is suffering low public support ratings.

Voter turnout was reported at 42.78 percent, up 7.27 percentage points from the previous mayoral race.

Shimizu, 47, a former member of the Saitama Prefectural Assembly and backed by the DPJ's prefectural chapter, left the Liberal Democratic Party in March.

Mayor Soichi Aikawa, 66, was seeking a third term. He was supported by the local organizations of the LDP and New Komeito.

The other candidates were Fukuyo Nakamori, a former Lower House member from the LDP; Yutaka Matsushita of the Japanese Communist Party; Nobumi Kusakabe, a former city assembly member; and Shumei Takahashi.