Should Osaka defeat Anisimova, she will become the first player to reach a Grand Slam final after becoming a mother since Victoria Azarenka made the 2020 US Open showpiece, which Osaka won.
And if the four-time major winner goes all the way in New York, she will be the first player since Kim Clijsters (in 2009, 2010 and 2011) to have won a Slam after giving birth.
Having struggled to put a dent in Muchova’s serve earlier in the first set, Osaka pounced decisively at 5-4 – going 0-40 up and closing out the opener at the second time of asking.
Muchova, who began grimacing because of an issue with her left leg in the sixth game, called for the trainer and received medical attention off court.
She returned with heavy strapping on her thigh, but it didn’t seem to hinder her tennis as she opened the second set with an early break.
Osaka struck back immediately, however, and there was little to separate the pair until a frustrated Osaka conceded serve at 4-4 with a series of unforced errors.
But, as Muchova stepped up to serve and force a deciding set, Osaka regained her composure and bounced back aggressively, breaking to love to level the set.
She took control in the tie-break, opening up a 4-1 lead which proved enough for her to wrap up the victory with a beaming smile.
“It was an incredibly difficult match,” Osaka added in her on-court interview. “She’s one of the best players in the world – every time I play her it’s so difficult.
She joked: “Last year she beat me here when I had one of my best outfits, so I was really upset.”