Of the elite players, Azarenka might push Williams hardest, but clearly it is not yet hard enough.

“I will do anything I can, anything, to be able to not just beat Serena but to win Wimbledon,” Azarenka said. “I will do anything to win Grand Slams. I’m going to work hard. This just gives me extra motivation.”

She is already tapping into Williams’s former brain trust, hiring Sascha Bajin, Williams’s longtime hitting partner and close friend, earlier this season. With Azarenka’s coach Wim Fissette home in Belgium after the birth of a child, Bajin played a more central role at Wimbledon and warmed up Azarenka with big serves and advice on Tuesday.

“There’s nothing personal against Serena,” Bajin said recently. “It’s more a little bit weird off the courts, when you see the family and you see the agent, Jill Smoller, and Serena’s mom, and I still have to walk by and say hi, and then we go our separate ways. That is more a little bit of the hard part.”

But the really hard part is beating Williams in a big match. It is now Sharapova’s turn to take another shot, and her record against Williams is even worse: 2-17, with few classics in the mix.

She has not beaten Williams in 11 years, not since 2004, the year she became a star by winning Wimbledon at age 17. Williams, at this late stage, has to be deep inside her head, and if Sharapova is to have any serious chance, she will have to lift her level in a hurry after her shaky, error-filled victory over CoCo Vandeweghe in Tuesday’s first quarterfinal on Centre Court.

Mouratoglou at least provided Sharapova with some bulletin-board material.

“She does not have a mental block against Serena,” he said. “Serena simply plays tennis much better than she does. For me, Azarenka is much better than Sharapova. There’s no discussion. Sharapova is a great champion. She has great qualities. She fights incredibly and has tremendous mental strength. But at some stage, her level of play hits a ceiling.

“That said, Serena is not immune to a bad match, right? All streaks have to end, but even if she has a bad match one day and loses, we cannot say there is not an enormous gap in their level of play.”