Tennis is not as big in Japan as baseball, soccer or sumo, but Osaka's 6-2 6-4 semi-final win over Keys made the front pages of major local newspapers on Thursday - although it was dwarfed by news of the quake that struck the northern island of Hokkaido earlier that day.
What the 2018 final will forever be remembered for is the way Williams clashed with chair umpire Carlos Ramos, demanding an apology after he initially issued a warning for a code violation in the second set's second game for receiving coaching, which is not allowed during Grand Slam matches. She later insisted that Ramos would "never, ever be on another court of mine as long as you live..." She then snapped her racket in half, resulting in a point violation. "But then when I hugged her at the net ... anyway, when I hugged her at the net, I felt like a little kid again".
"I was coaching but I don't think she looked at me", he said. In a semi-final against Kim Clijsters in 2009, she was penalised for threatening a line judge and put on a two-year probation. "I get the rules but I'm just saying that it's not right", Serena said to supervisor Brian Earley.
"I'm not at liberty to talk about it".
There was much riding on the match for both women, with Osaka bidding to become the first man or woman from Japan to lift a Grand Slam singles title and Williams poised to equal Margaret Court's record of 24 major titles. A tearful Williams chalked the penalty up to being targeted for her gender during a discussion with U.S. Open officials.
While Brennan says Osaka deserved the win, she also believes Serena's punishment is one the major concerns of this year's match.
Williams streaked into the US Open having won the Australian Open and Wimbledon that year and chasing a second straight title in Flushing Meadows.
She added in her post-match news conference that she had asked Mouratoglou why he said he was coaching her. He's never (taken) a game from a man because they said, 'thief.' For me, it blows my mind. "I know that she was frustrated about the way the match played out, but the way she stepped up after the final and gave full credit to Naomi for a match well-played speaks volumes about who she is".
Another chance came and went in the eighth game and, although Keys was now serving superbly, she just could not find a way through. You know, she just won.
"Cornet should be able to take off her shirt without getting a fine".
The WTA said Williams and U.S. Open champion Naomi Osaka both have "great integrity".
Earlier in the day Japan's wheelchair tennis ace Shingo Kunieda beat Nicolas Peifer 2-6, 6-4, 7-5 to claim his seventh U.S. Open title.
As the pro-Williams crowed booed the trophy ceremony announcer, Osaka was tearing up herself, but Williams urged the spectators to show the young champion respect.
"I just wanna tell you guys she played well, and this is her first Grand Slam", as she, too, appeared to become emotional amid the ensuing cheers from the audience.