Six races remain in the regular season.
Byron finished 11th at New Hampshire, one spot behind Reddick, but Byron extended his advantage on Reddick by five points. Byron scored six stage points, while Reddick scored none.
Jimmie Johnson fell to 25 points behind Byron for the final spot in the Cup playoff grid. Johnson overcame a spin after contact with Clint Bowyer to run in the top 10 but lost four spots in the final 20 laps to finish 12th.
“Good fight today guys,” Johnson told his team on the radio after the race. “Overcome a lot of (stuff) again.”
The series heads this weekend to Michigan International Speedway for two races. The Cup Series races there at 4 p.m. ET Saturday and at 4:30 p.m. ET on Sunday. Both races will be on NBCSN.
Ten of the 16 playoff spots have been secured by drivers who have won at least one race this year: Denny Hamlin, Kevin Harvick, Brad Keselowski, Joey Logano, Ryan Blaney, Chase Elliott, Martin Truex Jr., Alex Bowman, Austin Dillon and rookie Cole Custer.
Here is a look at the Cup playoff grid. Drivers shaded in green are locked in the playoffs. Drivers shaded in yellow are in a playoff spot based on their point total. Drivers shaded in red are outside a spot in the Cup playoff grid.