They were both outsiders in the starched white world of elite 1950s tennis, superb players but excluded from tournaments and clubs and shunned on the circuit because of their heritage. Angela Buxton, a white, Jewish English woman, was a granddaughter of Russian Jews who had fled the pogroms in the early 1900s; Althea Gibson, a Black American, was born in a sharecropper’s shack in South Carolina and grew up in Harlem.

Eventually, they found each other and forged a powerful doubles partnership. In 1956, they won the French Championship and Wimbledon, the jewel in the crown of a sport that had hardly welcomed them.

But for all Ms. Buxton’s prowess on the court — she was ranked in the women’s top 10 in the mid-1950s — she is best remembered for the long-lasting support and encouragement she gave Ms. Gibson, the first great Black player in women’s tennis, the first Black to win Wimbledon and, for a time, the No. 1 ranked female player in the world.

Ms. Buxton died at 85 on August 14 at her home in Fort Lauderdale.