Serena Williams was accessed a penalty point during her US Open finals match with Naomi Osaka after she smashed her racquet and allegedly received coaching.  She was furious with the announcement and let the chair umpire have it.

https://twitter.com/_MarcusD2_/status/1038539545044811782

Williams demanded an apology from Ramos and didn’t receive one.  She later called him a thief for accessing her the penalty point and was hit with a game penalty for her third violation.  

Williams accused the umpire of being sexist after the game penalty and had an emotional exchange with the referee.

https://www.youtube.com/watch?v=GLcf9YqL8Ek

Later her coach Patrick Mouratoglou admitted to coaching her, although he said she doesn’t believe she saw him, via Larry Brown Sports:

“I’m honest, I was coaching. I don’t think [Serena] looked at me, so that’s why she didn’t think I was (coaching). But I was, like 100 percent of the coaches on 100 percent of the matches. So we have to stop this hypocrite thing. “[Osaka’s coach] was coaching every point too.”

Williams, although she felt she was robbed, made sure the fans stopped booing her opponent and winner Osaka.  She did win the match after all and had absolutely nothing to do with the controversy.