The two-time Xfinity Series champion from Corning, California, led the final 16 laps and muscled away from Elliott en route to his first win in his 92nd start in NASCAR's premier series.
The 19-year-old Gibbs from Charlotte, North Carolina, led five of 48 over-scheduled laps as he executed a bold final lap pass on Larson for his eighth Xfinity career victory.
Elliott started 34th after failing to post a qualifying time, but methodically worked his way into the lead, passing Matt DiBenedetto on Lap 38, and then overtaking Kyle Busch with 17 to go.
The 18-year-old grandson of NASCAR Hall of Famer and team owner Joe Gibbs will return for an additional 14 Xfinity Series races throughout the 2021 season.
