The six-time US Open champion Serena Williams aiming for a record-equalling 24th grand slam title, came into the final against Japan’s Naomi Osaka on Saturday as the heavy favourite.But it was wasn't to be as Osaka showcased her absolute best to defeat her American counterpart 6-2, 6-4 to become Japan’s first slam winner.However, the topic of discussion quickly shifted away from the sport's newest star as Williams’ argument with umpire Carlos Ramos has dominated the headlines.Williams was given a coaching violation early in the second set after a hand gesture from her coach Patrick Mouratoglou and docked a point when she smashed her racket after dropping serve at 3-3.Continuing the argument with the umpire during the drinks break, Ramos handed her a third violation for verbal abuse, resulting in a game penalty.She accused the match official of sexism, demanding an apology and later explained why she felt so strongly about it in her post-match press conference.The 36-year-old said: “I can’t sit here and say I wouldn’t say he’s a thief because I thought he took a game from me.“But I’ve seen other men call other umpires several things, and I’m here, fighting for women’s rights and for women’s equality and for all kinds of stuff. And for me to say ‘thief’ and for him to take a game, it made me feel like it was a sexist remark."He’s never (taken) a game from a man because they said, ‘thief.’ For me, it blows my mind.“But I’m going to continue to fight for women and to fight for us to have (equality)."Williams also referred to a separate incident earlier in the tournament when Alize Cornet was punished for taking her top off mid-match.“Like, [Alize] Cornet should be able to take her shirt off without getting a fine" Williams added. "This is outrageous, you know? And I just feel like the fact that I have to go through this is just an example for the next person that has emotions and that want to express themselves, and they want to be a strong woman.“And they’re going to be allowed to do that because of today. Maybe it didn’t work out for me, but it’s going to work out for the next person.”Williams' behaviour certainly caused a stir on social media with many former players and pundits of the sport divided on the subject.Nevertheless, it would appear the American won over a fair few journalists with her justification as many applauded her as she gave her final answer.