TOKYO - Former defense minister Shigeru Ishiba won Japan's ruling Liberal Democratic Party (LDP) presidential election on Friday, virtually ensuring that he will become the country's next prime minister.

The 67-year-old lawmaker, in his fifth attempt to lead the party, was elected as the new LDP president by securing 215 votes in a runoff to defeat his female contender Sanae Takaichi, who received 194 votes.

As the LDP-led coalition constitutes a majority in both chambers of the parliament in Japan, the new party president is almost certain to be elected prime minister in the extraordinary Diet session scheduled to be held on Oct 1, succeeding the incumbent Fumio Kishida, who is not seeking re-election due to mounting criticism over the LDP slush fund scandal.

LDP parliamentarians cast 367 votes in the first round of voting, while another 368 votes were allotted to rank-and-file members. Ishiba, winning 154 votes, entered the runoff vote round with Takaichi who took the lead at 181 votes.

In the runoff voting, the LDP lawmakers cast the same number of votes, but the rank-and-file members' votes were reduced to one for each of the LDP's 47 prefectural chapters.

Shigeru won the final race with advantages in the votes from both LDP parliamentarians and local chapters.

43-year-old Shinjiro Koizumi, who is former environment minister and son of former Prime Minister Junichiro Koizumi, lost out in the nine-candidate race in the first round of voting earlier in the afternoon.