HAMPTON, Ga. (AP) — Austin Hill continued his dominant start to the NASCAR Xfinity season, holding off Daniel Hemric at Atlanta Motor Speedway on Saturday night for his third win in five races. Hill overcome a record-setting day of cautions in doubleheader Xfinity and truck series races. There were 11 cautions, the most for an Xfinity race in Atlanta, knocking out 12 drivers. Hill previously collected Xfinity wins at Daytona on Feb. 18 to open the season and at Las Vegas on March 4. Hill, a native of Winston, Georgia, added a home-track win to his strong start for the Richard Childress Racing team. The final caution came with eight…