US Open Tennis Predictions: Sabalenka vs. Pegula, Anisimova vs. Osaka semifinals

The 2025 US Open continues in New York City on Thursday, September 4 for Day 12 of the tournament and the women's semifinals at Flushing Meadows. The fourth and final Grand Slam of the year runs through to Championship Sunday on September 7 and as the tournament advances, we have the latest US Open best bets and tennis predictions.

The Dimers model has had a productive first half of the tournament, including a 2-0 day on our best High Value bets from Day 3 of the US Open, nailing Jannik Sinner as our top bet on Day 5 and another 2-0 result on Day 6 with bets on Carlos Alcaraz and Novak Djokovic and 2-0 again on Day 9 with Sinner and de Minaur before another 2-0 day on Tuesday and 2-0 again on Wednesday - that's a 6-0 run for the model right now!

After Amanda Anisimova upset Iga Swiatek in the quarterfinals, we're just two matches away from hitting a +2500 pre-tournament outright on Anisimova.

Add in Dimers’ biggest betting offering ever—expanded markets, new bet types, and broader sportsbook coverage—and there’s never been a better time to bet on the US Open.

Best Value Bets for US Open Women's Semifinals - Thursday, September 4

Today is the first day of the tournament where our model identifies no specific value in any bet, however, that may change if the odds or lines move, so be sure to check our US Open Semifinals Predictions before each match starts for the latest insights.

In place of value bets, we'll highlight each match outlook to help you find some betting angles on your own:

Aryna Sabalenka vs. Jessica Pegula Match Overview

• Date: Thursday, September 4, 2025
• Approx. Time: 7:00 PM ET
• Court: Arthur Ashe Stadium
• Moneyline Odds: Aryna Sabalenka -295, Jessica Pegula +250
• First Set Odds: Aryna Sabalenka -250, Jessica Pegula +200

Dimers' Probabilities

• Moneyline: Sabalenka: 75.1%,  Pegula: 24.9%
• First Set: 
• Spread: Sabalenka -4.5 (51%), Pegula +4.5 (49%) 
• Game Total: Over 22.5: 42%, Under 22.5 58%

Naomi Osaka vs. Amanda Anisimova Match Overview

• Date: Thursday, September 4, 2025
• Approx. Time: 8:10 PM ET
• Court: Arthur Ashe Stadium
• Moneyline Odds: Naomi Osaka -114, Amanda Anisimova +100
• First Set Odds: Naomi Osaka -125, Amanda Anisimova +100

Dimers' Probabilities

• Moneyline: Osaka: 53%, Anisimova: 47%
• First Set: Osaka: 52%, Anisimova: 48%
• Spread: Osaka -0.5 (55%), Anisimova +0.5 (45%)
• Game Total: Over 21.5: 52%, Under 21.5 48%

To find value bets, including some moneyline upsets and more, check out Dimers' Best Tennis Bets every day of the US Open.

Betting the US Open Smartly

Dimers’ “High Value” picks provide bettors with calculated opportunities, but not every match comes with an edge. Keep an eye on our Best Tennis Bets section for all the latest value and picks.

With Flushing Meadows buzzing, the 2025 US Open is primed for drama, and Dimers is giving bettors every tool they need to play it smart.

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