For Djokovic, the moment between the two great rivals was surprising and inspiring. Sharapova was officially inducted into the IHOF family, and her longtime rival Williams was in Newport to celebrate the occasion.

Novak Djokovic has challenged Serena Williams to return to tennis at the age of 43 after the American delivered a speech at Maria Sharapova's Hall of Fame induction. Williams hasn't played professionally since losing to Ajla Tomljanovic at the US Open three years ago.