Osaka won the match 6-3, 6-4 to advance to the Australian Open final for the second time. She has now won 20 consecutive matches, last losing in February last year.
“I don’t know if there’s any little kids out here today, but I was a little kid watching her play,” Osaka said of Williams on court after the win. “Just to be on the court playing against her for me is a dream.”
Williams, 39, embraced Osaka after the match. She then waved to the crowd as she departed, putting a hand over her heart.
Williams was asked in a post-match news conference if the gesture meant farewell.
“I don’t know. If I ever say farewell, I wouldn’t tell anyone, so,” she said.
Visibly emotional, Williams left the news conference after the next question.
Osaka is the heavy favorite in the final on Saturday, regardless of her opponent. She awaits the winner of the second semifinal between No. 22 seed Jennifer Brady of the United States and No. 25 seed Karolina Muchova of the Czech Republic.
Neither Brady, 25, nor the 24-year-old Muchova have reached a major final before.