Rui Naiwei

She is the strongest recorded female Go player, and is the only woman to have won one of the major open Go titles.

She achieved this by winning the 1999 Guksu title (the oldest and one of the most prestigious Go competitions in Korea), on the way beating Lee Chang-Ho and Cho Hun-hyun, the two strongest players in the world at the time.

After that, Chinese Feng Yun and Korean Park Jieun became the second and third female go players to reach 9 dan, following Rui Naiwei.

While the Nihon Ki-in did not allow her to play in any Japanese tournaments, she was able to make it to the semi-finals of the international Ing Cup in 1992.

[1] Rui's style tends to be extremely aggressive, and often characterized by large scale semeai.