In 1966, King defeated Dorothy "Dodo" Cheney (then 49 years old) for the first time in five career matches, winning their semi-final 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. She also won the women's singles in the Ojai Tennis Tournament. 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 the first of her six singles titles at Wimbledon and the first of twelve Grand Slam singles titles overall, defeating Court in the semi-finals 6–3, 6–3 and Maria Bueno in the final. King credited her semi-final victory to her forehand down the line, a new shot in her repertoire. She also said that the strategy for playing Court is, "Simple. Just chip the ball back at her feet." At the U.S. Championships, an ill King was upset by Kerry Melville Reid in the second round.