Bidding to equal Margaret Court's record of 24 grand slam titles – having last won a major in 2017 – Williams was overpowered 6-3 6-4 by third seed Osaka in Melbourne on Thursday.

It was Williams' first semi-final defeat at the Australian Open following eight consecutive victories in the final four of the year's opening slam.

The 39-year-old American star cut an emotional figure afterwards on Rod Laver Arena, where she held her hand on her chest and waved to the crowd after fans were allowed to attend following a five-day coronavirus shutdown.

Asked about the moment, seven-time Australian Open champion Williams told reporters: "The Aussie crowd is so amazing, so it was nice to see."

When pressed if it was a Melbourne farewell, Williams replied: "I don't know. If I ever say farewell, I wouldn't tell anyone."

A tearful Williams then suddenly ended her news conference after being asked about the match.

Williams was visibly and vocally frustrated against Osaka after seeing an early 2-0 lead slip.

Osaka reeled off five consecutive games and six of the next seven to close out the set before taking complete control against the former world number one.

Williams finished with 24 unforced errors against the three-time slam champion and 2019 Australian Open winner.

At the start of her post-match duties, Williams said: "I wouldn't say I was nervous. The difference today was errors. I made so many errors today.

"Honestly, it was opportunities where I could have won. I could have been up five-love. I just made so many errors."

"I felt like I was hitting well," Williams added. "I was hitting well this whole tournament. Even the first couple games I played well. Even then I had so many opportunities.

"I don't know. Just made too many mistakes there, easy mistakes. Not like I was on the run or anything, they were just easy, easy mistakes."