The sports ace hit headlines on Saturday, September 8 after becoming embroiled in a heated dispute with chair umpire Carlos Ramos, who penalised her on three occasions for allegedly breaking the competition's code of conduct during her women's finals match against 20-year-old Naomi Osaka in New York.
The confrontation kicked off with the insinuation that Serena had been cheating early on in the second set after her coach, Patrick Mouratoglou, was spotted making a motion with his hands, appearing to try and send a signal to the new mum from the stands - a violation of the coaching rule.
Offended at the suggestion, Serena protested the claim and smashed her racket on the ground, costing her a point in the next game, before accusing Ramos of stealing the point away from her as she branded him a "thief" - which led the umpire to penalise her for verbal abuse and award a game to Osaka. The emotional 23-time Grand Slam champ deemed the move sexist, insisting he had previously let off male players for using much harsher language.
Osaka eventually won the match 6-2, 6-4, becoming the first Japanese player to win a Grand Slam singles tournament, but her victory was overshadowed by the bitter umpire fight, and the rising star wiped away tears during the trophy presentation as the crowd's angry boos at Ramos' actions echoed around the stadium.
Serena, who encouraged fans to halt the jeers, tried to comfort Naomi and insisted she "deserved to win", and during her post-match press conference, Williams explained she felt the need to point out Ramos' hypocrisy to even the playing field for future female players.
Her professionalism during the prizegiving ceremony led a number of her famous friends to take to social media to show their support, and thank her for continuing the fight for equality.
Kelly Rowland, who had been seated in Serena's box with actress La La Anthony during the match, was among the first to applaud her actions on Instagram.
"SERENA!!! CLASS ACT!! ALWAYS A CHAMPION!!!!" the former Destiny's Child star wrote alongside an image of her pal. "I (LOVE) YOU!!! WE ALL (LOVE) YOU!!! (The Ump (sic) was a weak soul, what a double standard!!!!) #BS (bulls**t)".
Alicia Keys, who was also in attendance at the finals, also heaped praise on the athlete, writing, "@serenawilliams You are THE epitome of grace and prowess!!! You are an inspiration to all of us. Your purpose to be a leader and a light is a gift to the world!! We love you and thank you for sharing your greatness and spirit ! Congratulations Queen!!!"
And Ciara added, "Proud of my friend @SerenaWilliams for standing up and being strong tonight. A true inspiration to many of us women. A new day is coming. #Equality".
Actress America Ferrera retweeted a news article about the financial penalty on Sunday and remarked, "When a woman dares to act as men are allowed to... she pays for it.
The on-court confrontation has since landed Serena a $17,000 (£13,200) fine from officials at the United States Tennis Association governing body, drawing further criticism from social media users.