WTA US Open Wednesday Betting Preview: Finalizing the Final Four

And then there were six on the WTA side. It's been an entertaining U.S. Open, right from the first afternoon, when Kaia Kanepi upset No. 1 seed Simona Halep.

Only one of the two Americans in action Tuesday advanced to the semis. Sloane Stephens was upset in the oppressive New York heat by Anastasija Sevastova, who will now make her first major semifinal appearance.

The other result wasn't as surprising. After a slow start, Serena Willliams rolled past Karolina Pliskova — and she's now the clear favorite to take home her seventh U.S. Open championship.

While Serena will be seeking her 24th Grand Slam singles title, the five other women left standing have a combined total of zero. And three of the four competing on Wednesday have never even appeared in a major semifinal.

Let's take a closer look at Wednesday's action, starting with the first match, between two first-time Grand Slam quarterfinalists.

Naomi Osaka (-225) vs. Lesia Tsurenko (+190)

Time: Noon ET
H2H: Osaka leads 1-0 (2014 ITF hard court)

Considering neither player has ever made a Grand Slam quarterfinal, nerves could get out of control — especially toward the business end of sets.

On Monday, Osaka took on Aryna Sabalenka in a battle of 20-year-old rising superstars. That match lived up to the hype, and Osaka simply stayed a little steadier. Her serve also held up better under pressure late, which could be the difference today in a potential nerve-fest.

Tsurenko also had a dramatic three-set victory, over teenager Marketa Vondrousova. The Ukrainian did take her third medical timeout of the tourney in that match for her taped right arm. I have no idea what the issue is — and it seems Vondrousova doesn't either.

Osaka and Tsurenko could not have more opposite games. Osaka is a powerful, aggressive player. Tsurenko plays defense and angles. Osaka is very introverted and keeps her emotions in check on the court. Tsurenko leaves everything on the court, and she plays up the dramatics to an extreme degree, as evidenced by Vondrousova’s quote.

Handicapping how a player will deal with nerves on a brand new stage is difficult. However, we did see Osaka perform at her best earlier this year when she won at Indian Wells (which some call the "fifth major") by beating top talents Pliskova, Halep and Daria Kasatkina in the last three rounds.

The U.S. Open is a bigger stage, but many players have stated that the courts play pretty similarly. Osaka specifically mentioned in her most recent post-match interview that she drew upon her Indian Wells experience, which she thought gave her an edge over Sabalenka.

Osaka will also have a very pro-Japanese crowd behind her in Queens. That contingent helped her Monday when she played following Japanese men's star Kei Nishikori, who will play after her today.

The combination of superior talent, a supporting crowd and more experience on the bigger stage makes Osaka a solid -275 favorite. I think she’s a worthwhile parlay piece to pair with a football moneyline this weekend.

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Madison Keys (-275) vs. Carla Suarez Navarro (+230)

Time: 7 p.m. ET
H2H: Keys leads 3-0 (2-0 on hard courts)

Keys' dream draw continues in the quarterfinals. The 2017 U.S. Open runner-up played her best match of the tournament Monday, dominating Dominika Cibulkova in straight sets. If she’s on her game, she should do the same to her opponent today.

Suarez Navarro looked solid Monday, but she benefited a great deal from an out-of-sorts Maria Sharapova. The Spaniard will need help once again if she wants to reach her first Grand Slam semifinal. CSN is a lifetime 0-6 in major quarterfinals, including her lone other run to this stage at the U.S. Open in 2013.

Keys owns a 3-0 head-to-head record, but all three matches went three sets. That said, Keys is a much better player than she was at the 2016 Olympics when these two last met.

When Sharapova actually struck the ball cleanly, it clearly flustered Suarez Navarro into some shaky groundstrokes. If Keys can hit balls deep with just average power, she'll control the points throughout.

I have Keys as a -250 favorite, so I don't see any value either way. The American has certainly tripped herself up as a sizable favorite before — and Suarez Navarro can take advantage of any hiccups, as she did against Sharapova.