American legend Serena Williams remains on track to win her record-tying 24th Grand Slam women's singles title, but she now faces second-seeded Simona Halep in the 2021 Australian Open quarterfinals early Tuesday morning. Williams is listed as the -137 favorite, while Halep is a +110 underdog.

There are plenty of other ways to bet the match, including a +200 play on Williams to win it in two sets and +105 on Halep to win the first set. Before you make your 2021 Australian Open women's quarterfinals picks, you NEED to see who Gavin Mair is picking. 

Mair is the international women's tennis expert who called unseeded Jelena Ostapenko (80-1) winning the 2017 French Open, Naomi Osaka (32-1) winning the 2018 U.S. Open, Bianca Andreescu (20-1) winning the 2019 U.S. Open, plus many other prescient calls.

Prior to the women's final in the most recent grand slam, the French Open, Mair picked Iga Swiatek to win (-163) and win in straight sets (+140), and he was right on both counts.

Now, Mair has broken down the latest 2021 Australian Open women's quarterfinals odds and released his coveted best bets for Williams vs. Halep. His picks include a play on the outright winner and advice on how many sets the match will go! You ABSOLUTELY need to see all of Mair's picks and analysis of the 2021 Australian Open before you bet.

So who wins the Williams-Halep quarterfinal? And which pick could lead to a huge return? ... Join SportsLine right now to see Gavin Mair's top 2021 Australian Open quarterfinal picks, all from the acclaimed expert who hit it big in the last grand slam women's final! -- Use promo code TENNIS to get your first month of SportsLine for a buck!