Blaney erased the sting of a disappointing runner-up finish last week in Indianapolis by maintaining his lead through a second green-white-checkered finish on the 0.894-mile oval.
Blaney won after finishing second three times in his other six Xfinity starts this season.
Regan Smith was second, followed by Brian Scott, Ty Dillon and Brendan Gaughan
Fifty-one-year-old Kenny Wallace, the career Xfinity starts leader with 547, finished 15th in the last race of his NASCAR career.
