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. Byron led 141 laps. Brad Keselowski was third. He came into the race needing a win to get into the playoffs.
