Williams' surprise appearance to induct Sharapova was "months in the making" and required the code name of another female icon.

Williams and Sharapova were not always on great terms, each admitted in their speeches, but came to share a mutual respect and a growing friendship since retiring.

The red carpet rolled out at Arthur Ashe Stadium. Smoke blew from the cannons. Then Maria Sharapova emerged in a mid-length black dress, its collar reflecting light back into the tennis stratosphere,