OSAKA - Former Osaka Governor Toru Hashimoto won a landslide victory in the Osaka mayoral race held Sunday, defeating incumbent Kunio Hiramatsu, final returns showed Monday.

Hashimoto secured 750,813 votes, while Hiramatsu got 522,641 votes.

In a gubernatorial election held the same day, Ichiro Matsui, a 47-year-old former Osaka prefectural assembly member and Hashimoto's close aide in a local party, beat six rivals to get an easy win. Voter turnout for the mayoral election reached 60.92 percent, up 17.31 percentage points from the previous poll in November 2007, while the figure for the gubernatorial race was 52.88 percent, up 3.93 points from the previous poll in January 2008, according to the election boards of the city and the prefecture.

During the election campaign, Hashimoto stressed his "One Osaka " proposal that both Osaka Prefecture and the city of Osaka need to be reorganized into a metropolitan government to cut dual administrative functions and costs, while promising a growth in the region's economy.

Hashimoto, also the leader of the political party Osaka Restoration Association (Osaka Ishin no Kai) is pushing to renew a traditional administrative structure for the whole Osaka region.

Hiramatsu, 63, who ran for reelection as an independent, was backed by local chapters of the ruling Democratic Party of Japan and the main opposition Liberal Democratic Party.

Hashimoto, 42, who won the Osaka gubernatorial election in 2008, stepped down as governor in late October, about three months before his four-year term of office was due to expire, to run in the mayoral race.

At a press conference to declare his victory, Hashimoto vowed to change Osaka and push forward the plan to overhaul the local administration system. Matsui also told the press conference that he will "firmly maintain" the policies upheld by Hashimoto as governor.