Taro Aso, the outspoken former foreign minister, won a landslide poll to take over from Yasuo Fukuda as leader of the Liberal Democratic Party (LDP) and the next prime minister of Japan.
Mr Aso, the grandson of a former prime minister, won 351 of the 525 valid votes cast by LDP legislators and chapters, reports Reuters.
Following his victory, he said he felt he was fulfilling his destiny.
"But the LDP, as the government party, must resolutely fight the [opposition] Democratic Party in the next election, and only when we have won that election will I have fulfilled my destiny," he commented.
Mr Aso is almost certain to be the next prime minister due to his party's majority in Japan's parliament. He will be the country's third prime minister in a year.
In the poll, economics minister Kaoru Yosano came second with 66 votes, while former defence minister Yuiko Koike - in a bid to become the first female prime minister of Japan - came third with 46 votes.
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