TOKYO (AP) — Former world No. 4 Kimiko Date says she will retire from competitive tennis after next month's Japan Women's Open.

The 46-year-old Date, who retired once in 1996 and made a comeback in April 2008, wrote on her official blog on Monday that she has been hampered recently by pain in her knee and shoulders.

Date, who underwent a second surgery on her left knee in April last year, said: "This will be the last tournament of my second challenge now that I have made the difficult decision to retire."

Date, who has won eight WTA Tour titles, reached the singles semifinals in three of four Grand Slams — the Australian Open, the French Open and Wimbledon. She placed fourth in the world in November 1995 for her highest singles ranking.

The Japan Women's Open takes place from Sept. 11-17 at Ariake Colloseum in Tokyo.