Billie Jean King the match proved to her that she was "good enough to be the best in the world. I'm going to win Wimbledon next year." She won six tournaments during the year. For the first time in 81 years, the annual convention of the United States Lawn Tennis Association overruled its ranking committee's recommendation to award her the sole U.S. No. 1 position and voted 59,810 to 40,966 to rank Nancy Richey Gunter and King as co-U.S. No. 1. Six of King's Grand Slam singles titles were at Wimbledon, four were at the U.S. Championships/Open, one was at the French Open,
Billie Jean King during this period and was the runner-up in 36 other tournaments. In 1966, King defeated Dorothy "Dodo" Cheney (then 49 years old) for the first time in five career matches, winning their semifinal at the Southern California Championships 6–0, 6–3. King also ended her nine match losing streak to Margaret Court by defeating her in the final of the South African Tennis Championships. At the Wightman Cup just before Wimbledon, King defeated Virginia Wade and Ann Haydon-Jones. After thirteen unsuccessful attempts to win a Grand Slam singles title from 1959 through 1965, King at the age of 22 finally won