NEWTON, Iowa — William Byron fought off fuel worries in the closing laps to win the NASCAR Cup Series race Sunday at Iowa Speedway.

Byron went the last 144 laps of the 350-lap race without a stop en route to his second victory of the season — he won the Daytona 500 in February — and 15th overall. He also took the season points lead from Hendrick Motorsports teammate Chase Elliott.

Byron lost gambles on fuel twice this season, at Michigan and Indianapolis , but held on with the help of a caution-filled final stage to win by 1.192 seconds over pole-sitter Chase Briscoe.

“We needed one to go our way,” said Byron, who led 141 laps.

Credit: AP Photo/Bryon Houlgrave William Byron celebrates after winning a NASCAR Cup Series race at Iowa Speedway, Sunday, Aug. 3, 2025 in Newton, Iowa

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