TOKYO - Former prime minister Shinzo Abe is now guaranteed a second shot at the premiership, following his upset victory in the presidential election of the opposition Liberal Democratic Party (LDP).
Mr Abe, 58, beat former defence minister Shigeru Ishiba 108-89 in a run-off vote yesterday.
It is the first time in the LDP's history that a former premier has been picked to helm the party.
In the first round of voting, Mr Ishiba, 55, was the overwhelming choice of the rank and file, but he failed to secure the support of LDP lawmakers in the crucial run-off vote.
Yesterday's election was closely watched, as the LDP's choice of leader could affect its chances of winning the general election that must be held no later than next August.
Even though the LDP currently leads the ruling Democratic Party of Japan in the popularity stakes, it still needs a leader who will go down well with voters.
The choice of the LDP's rank and file was considered an important guide to picking its new president.
In the 2001 party election, LDP lawmakers changed their minds at the last minute and backed Mr Junichiro Koizumi when it became clear that he had the overwhelming approval of party members.
Mr Koizumi went on to win the general election, and was prime minister for five years.
But this time, LDP lawmakers ditched Mr Ishiba even though he had 55 per cent of the members' votes, twice what Mr Abe had.
It remains to be seen if Mr Abe will be an asset or liability to the LDP at election time.
Political commentator Atsuo Ito suggested that the choice of Mr Abe may turn out to be a mistake.
"The three candidates who lost in the first round were able to use their votes in the run-off to give Mr Abe the victory, ignoring the fact that Mr Ishiba was the members' favourite," said Mr Ito.
In addition, Mr Abe is handicapped by the fact that as a former premier, he symbolises the old LDP, which Japanese voters strongly rejected in the 2009 General Election.
Mr Abe is also still dogged by criticisms that he irresponsibly quit as prime minister in September 2007, after barely a year in office, following the LDP's defeat in the Upper House polls in July that year.
In his victory speech yesterday, Mr Abe offered an apology. "My victory today does not wipe away that responsibility of five years ago. But with it in mind, I will do my best to win back the administration," he pledged.
Mr Abe is expected to put renewed pressure on Prime Minister Yoshihiko Noda to dissolve Parliament and hold early elections.
There is also some doubt over Mr Abe's medical fitness.
In 2007, he was said to have thrown in the towel partly because he reportedly had a form of inflammatory bowel disease that causes constant diarrhoea and was difficult to cure.
Although he now claims to be in good health, he has not provided any medical proof.
Moreover, his brief premiership was marked by criticisms over mismanagement of the national pension programme and him placing friends instead of more capable people in Cabinet positions.
A hawkish politician, Mr Abe talks constantly about strengthening Japan's security alliance with the United States and revising its so-called "Peace Constitution", which bars the country from going to war.