It was Smith's second win of the year and 11th top-10 finish in 13 starts. He took the lead with 13 laps remaining when Parker Kligerman had to pit, and although Larson closed the gap a bit toward the end, he wasn't able to overtake Smith's No. 7 Chevrolet.
The 125-lap, 250-mile race was run under threatening weather conditions, but drivers were able to finish with no delays. Paul Menard was third, followed by Kyle Busch and Trevor Bayne.
Smith's final margin of victory was 0.331 seconds. He also won at Talladega in May.