A woman from Yamaguchi Prefecture has become the first centenarian in the world to complete a 1,500-meter swim in a 25-meter pool.

Competing in Matsuyama, Ehime Prefecture, Mieko Nagaoka, 100, finished the race in a world-record time of 1 hour, 15 minutes and 54 seconds, according to the Japan Masters Swimming Association.

Nagaoka, who was the only swimmer competing in the 100- to 104-year age bracket in Saturday's event, did the entire race using the backstroke.

Her time is expected to be recognized by Guinness World Records after she submits an application to the international swimming federation.

Nagaoka, a resident of Tabuse, began swimming at the age of 80 as part of rehabilitation for her hurt knee. At that time, she could barely swim. Last year, she completed a 1,500-meter swim in a 50-meter pool in the women's freestyle category.

"I want to swim until I turn 105 if I can live that long," she said after the race.

With her latest achievement, Nagaoka will hold world records in 25 swimming events.