Williams took a mid-game medical timeout for the Achilles tendon issue in the Deciders’ second game and eventually trailed 2–0. Unlike her previous three rounds, this time there was no return for the 38-year-old.
Williams has lost his last four Grand Slam finals as he tried to match Margaret Court’s 24 all-time record, but semi-final defeats are rare in majors. She fell to 33-6.
Azarenka reached her first Grand Slam final since losing to Williams in the final of the 2013 US Open.
She will take on Naomi Osaka, who defeated Grand Slam semifinalist Jennifer Brady 7-6 (1) 3-6 6-3 for the first time. Osaka won the crown by defeating Williams in the controversial closing ceremony in 2018.
This warmup is a remake of the finals of the Western and Southern Open, which also played on the site of the US Open during the coronovirus epidemic as part of the tournament bubble.
Osaka, however retreated with a hamstring injury to hand over the title to Azarenka.
Thursday’s matches were played on the roof at Arthur Ash Stadium due to rain.