The Australian Open semifinals begin on Wednesday night, headlined by the match between the 10th-seeded Serena Williams of the United States and the third-seeded Naomi Osaka of Japan. It will be their first Grand Slam meeting since the 2018 United States Open final, an Osaka victory in which Williams received three penalties from the chair umpire.
The victor will face the winner of the other semifinal match: between No. 25 Karolina Muchova of the Czech Republic and No. 22 Jennifer Brady of the United States.
Here’s what to look for in the match, which will start around 10 p.