Gibbs led only the last lap.
It is the second win of the year for Gibbs and sixth of his career.
Sieg fell to 10th on the final lap.
Daytona winner Austin Hill finished second and was followed by AJ Allmendinger, Riley Herbst and Landon Cassill. Mason Massey finished a career-best sixth. His previous best in 26 previous Xfinity races was 17th. Brandon Jones was seventh. Kyle Weatherman tied his career-best finish of eighth.
The 172-lap race (extended nine laps by overtime) featured 10 cautions.
STAGE 1 WINNER: Josh Berry
STAGE 2 WINNER: AJ Allmendinger
NOTABLE: Justin Allgaier‘s streak of 16 consecutive top-10 finishes ended when he was collected in a multi-car crash late in the race. Allgaier finished 34th.
NEXT: The series competes March 26 at Circuit of the Americas (4:3) p.m. ET on FS1)
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Ty Gibbs wins Atlanta Xfinity race with last-lap pass originally appeared on NBCSports.com