Former TV presenter and cabinet minister Yoichi Masuzoe has won the election for Tokyo governor by a wide margin.
The vote had been seen as a test of popular sentiment on nuclear power.
Mr Masuzoe agrees with government plans to restart Japan's nuclear reactors, while his two closest rivals campaigned on an anti-nuclear platform.
He won 2.1 million votes, more than the combined total of his two nearest rivals.
A field of 16 men fought a two-week campaign to become chief executive of the city of 13 million people.
Turnout in Tokyo was low at 46% as the capital, like much of Japan, is enveloped in its heaviest snowfall in decades.
The weather was to blame for at least five deaths and 600 injuries across the country by early Sunday, reports said.
Relief for Abe
Following the release of exit polls, Mr Masuzoe, 65, appeared smiling before cameras in Tokyo.
He promised to make Tokyo "the number one city in the world''.
"There is no time to spare for relishing the result," he added. "I have to work with a sense of the heavy responsibility the post brings."
Mr Masuzoe has the backing of Prime Minister Shinzo Abe's conservative Liberal Democratic Party.
Mr Abe told reporters he wanted Mr Masuzoe to work on issues such as "low birth rate and longevity as well as economic revitalisation".
Mr Masuzoe's closest rivals were lawyer Kenji Utsunomiya, 67, who came second, and former Prime Minister Morihiro Hosokawa, 76, who was backed by popular fellow former Prime Minister Junichiro Koizumi.
Mr Utsunomiya received around 982,000 votes, while Mr Hosokawa received 956,000, AP news agency reported.
The victory for Mr Masuzoe will come as a relief for Mr Abe, who suffered a rare setback in another local election last month.
Correspondents say much of the voting is likely to have been based on issues like the economy and social welfare programmes.
But the starkest difference between the men was their stance on nuclear power. Public support for nuclear technology has fallen sharply since a tsunami caused a disaster at the Fukushima nuclear plant in March 2011.
The post of Tokyo governor became vacant in December when Naoki Inose stepped down after admitting wrongdoing in accepting an undeclared 50m yen ($500,000; £300,000) from a scandal-hit hospital tycoon.
The new governor is expected to spend much of his time preparing for the 2020 Summer Olympics, with construction projects and the renovation of the city's infrastructure already under way.