Underdog Promo Code FOXSPORTS: Play $10, Get $50 on Any NBA Opening Day Game Including Celtics vs. Pistons

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The NBA is back, and opening day brings a tripleheader of matchups for basketball fans to enjoy. New users can use the Underdog promo code FOXSPORTS, play $10 and get $50 in bonus entries to celebrate the start of the 2026-27 season.

The Boston Celtics and Detroit Pistons headline the opening matchup, with Jayson Tatum and Cade Cunningham among the stars to watch as both teams look to start the season strong. 

The action continues with the Philadelphia 76ers facing the New York Knicks before the Oklahoma City Thunder and San Antonio Spurs close out opening night. 

Get ready for a new season of NBA action with Underdog. New users can use promo code FOXSPORTS and play $10 to receive $50 in bonus entries. Whether you're following the Eastern Conference showdown in Detroit or the Western Conference clash in San Antonio, there's plenty of basketball to get excited about.

How to Sign Up and Claim the Underdog Promo Code

1. Click "Claim Now" or visit the Underdog site and use promo code FOXSPORTS
2. Download the Underdog app (iOS or Android) and complete registration (name, email, date of birth, address, last 4 of SSN if required) and account verification.
3. Once your account is verified and you play $5, you will receive $10 in bonus bets.
4. Repeat this process each day for 10 days to earn $100.
5. Any winnings from bonus-fund entries become withdrawable once play-through or contest requirements are satisfied.
6. For more information, visit our Underdog promo code page.