Serena Williams underdog vs. Naomi Osaka in Australian Open semis

Serena Williams will be in the rare position of underdog when she plays in her first Australian Open semifinal since 2017 on Thursday.

The 10th-seeded Williams beat second-seeded Simona Halep in straight sets on Tuesday. Next up for the seven-time champion in Mebourne? That would be third-seeded Naomi Osaka, who has won 19 consecutive matches.

Osaka has been installed as the -159 favorite to beat Williams (+130) by DraftKings, with a straight-sets victory having the shortest odds at +160. Osaka winning in three sets is being offered at +320, with Williams offered at +300 to win in straight sets and +410 to win in three.

Naomi Osaka
REUTERS/Loren Elliott

Osaka has won two of three previous meetings and has won each of the three previous Grand Slam tournaments in which she has reached quarterfinals. She lost only four games to Su-Wei Hsieh in the quarterfinals and has not lost more than three games in a set in any match other than her grueling three-set test against former grand slam champion Garbine Muguruza in the fourth round.

Williams, 39, scored an impressive 6-3, 6-3 victory over Halep after struggling to a three-set win against Aryna Sabalenka in the fourth round. Like Osaka, Williams moved through each of her first three matches without dropping a set.

Serena Williams In Pursuit Of History

Williams is pursuing a record-tying 24th Grand Slam championship. She is being offered at +275 to win the title by DraftKings, with Osaka the +155 favorite.

“I feel like I needed to have a good performance today, especially after my last match against her,” Williams said after beating Halep. “So it was really important to try to play well today. … I knew I couldn’t play worse (than last time). So that was a good thing.”

–Field Level Media (@FieldLevelMedia)