Serena Williams' appearance at Maria Sharapova's induction into the International Tennis Hall of Fame came as a surprise. The now-retired WTA stars once shared a fierce rivalry, but today, their bond is one of mutual admiration and respect. Williams showing up at Sharapova's Hall of Fame induction led to many tennis fans turning emotional.Sharapova, a former No. 1 and five-time Major champion, was officially inducted into the International Tennis Hall of Fame on Saturday, August 23. The Russian was on hand to deliver her induction speech at Newport, Rhode Island. However, little did she know that her fierce yesteryear rival Williams would be the one to deliver the introduction speech.Serena Williams' words summed up the impact of Maria Sharapova on the world of tennis and beyond. The 23-time singles Slam winner also briefly touched on their rivalry and later shared a warm embrace with the Russian.Fans on X (formerly Twitter) became emotional upon seeing the former rivals sharing such heartfelt moments together."Excuse me why am I crying? 😭 And where can I see the full thing? Serena looks amazing," one fan wrote."This is so beautiful to see. Friendship and humanity above competition and past rivalries. Tennis is just a game after all," commented another."I don’t know if I could be this big of a person. But, kudos to Serena," another fan chimed in."One of biggest rivalries in not just tennis but women’s sport in general, gosh miss seeing them on the court not the same now," wrote one."Maria Sharapova’s whole book is about Serena. What a treat for her to have Serena at her ceremony," another added."This shows that no matter the rivalry, there is huge respect, I wish the fans realize this and stop hating on each other," weighed in yet another fan.Serena Williams poked fun at Maria Sharapova's iconic grunt during introduction speech at Russian's Hall of Fame inductionSerena Williams delivering her introduction speech at Maria Sharapova's induction ceremony at the International Tennis Hall of Fame (Source: Getty)While delivering the introduction speech to officially induct Maria Sharapova to the International Tennis Hall of Fame, Serena Williams teased the Russian, bringing up her former rival's loud grunt. Williams said:"It launched one of the most talked about and controversial rivalries in tennis. For more than a decade and a half, every time we faced each other, the atmosphere shifted. It was thick, the tension was real, the fire was real and honestly, you could feel it, and by the way, you could hear it, with all of Maria's grunting."Williams' own tennis-playing career came to an end at the 2022 US Open with a shock upset the tennis legend suffered at the hands of Ajla Tomljanovic in the third round. Sharapova announced her retirement following an underwhelming outing at the 2020 Australian Open.