Subsequently, it became a men-only event and integrated into the ATP's professional tennis circuit.

The inaugural edition of the event, known as the Pacific Southwest Championships, was organized by Perry T. Jones and held at the Los Angeles Tennis Club (LATC) starting in October 1927.

[2] The tournament was usually held in September and hosted the top men (and until 1975, women) in the world.

1 tennis players: Bill Tilden, Ellsworth Vines, Don Budge, Fred Perry, Jack Kramer, Pancho Gonzales and amateur champions Roy Emerson and Barry MacKay (tennis).

[2] In the open era, the tournament was won by Rod Laver twice, a second and third time by Gonzales, Stan Smith, Arthur Ashe, Jimmy Connors, John McEnroe, Pete Sampras, Richard Krajicek, and Andre Agassi.