The win qualified the Roush Fenway Racing driver in the 20-driver field for Saturday’s Sprint All-Star Race at Charlotte Motor Speedway.
Biffle, who started second, passed the pole-sitter shortly after the green flag and led all 20 laps of the first segment.
Clint Bowyer was second, followed by Paul Menard, Austin Dillon and David Ragan.
Biffle’s No. 16 Ford will not race in the second 20-lap segment, whose winner also will advance to the Sprint All-Star Race.
Biffle is mired in a slump that could be traced back nearly two years to his most recent win in June 2013 at Michigan International Speedway. He missed the Chase for the Sprint Cup last year and finished 14th in the points standings. He is ranked 21st in points this season with one top 10 (a 10th in the season-opening Daytona 500).
“I’ve never been so excited to win half a race in my life,” he said.