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.

Though Williams and Sharapova were rivals both on and off the court throughout their storied careers, they have unexpectedly emerged as friends since retiring. With their relationship now a friendship, Williams not only surprised Sharapova by attending her Hall of Fame induction, but gave a touching speech in her honor.

Maria Sharapova has entered the International Tennis Hall of Fame, with Serena Williams introducing her at the ceremony on Saturday night.