TOKYO (AP) Japan's Ai Miyazato says she has decided to quit the LPGA Tour at the end of the season because she lost her motivation for the sport after years of struggling to win again.
Miyazato, who was ranked No. 1 and captured 25 professional titles during her career, has not won a tournament in five years and said that lack of success has diminished her drive to keep going.
''I've been struggling to maintain my motivation for the past four or five years,'' she told a news conference in Tokyo on Monday, three days after the LPGA announced her decision to retire.
''Being a professional is all about results and lately I wasn't able to achieve good results.''
Miyazato joined the LPGA Tour in 2006 and has earned more than $8 million in her career but has fallen down the rankings and is currently outside the top 100.
She does not have a top-10 finish this season and had only one last year.
There were rumors in the Japanese media that Miyazato was retiring because she was getting married but the 31-year-old said she has no plans to tie the knot and her real reason for quitting was somewhat less romantic.
''I've found it hard to stay focused even in training which I could always do before,'' she explained.
Miyazato does not have a major title - her best results were ties for third at the Women's PGA Championship (2006, 2010) and the Women's British Open (2009) - but she is one of only nine players to make it to No. 1 since the women's world golf rankings were introduced in 2006.
Her nine LPGA Tour victories all came between 2009 and 2012, including five in 2010, when she was No. 1 three times for a total of 11 weeks.
Women's golf had been dominated by Annika Sorenstam and Lorena Ochoa in the years prior to Ochoa's retirement from full-time golf in April 2010. Miyazato was in her prime that year, winning four of the first nine LPGA Tour events she played.
She also won 15 times on the Japanese LPGA and won the World Cup of golf in 2005 but her most recent LPGA Tour event was the Lotte Championship in April where she finished tied for 34th.