Kenseth entered Sunday's race in first place of the Cup standings by four points over Jimmie Johnson. But Kenseth finished 20th, while Johnson was 12th.
So Kenseth, despite winning the first two races of the Chase for the Championship, now finds himself in second place of the standings, trailing Johnson by four points.
"I should've been smarter there, and I guess paid attention to points, but I'm not really wired like that," said Kenseth, who led 32 laps Sunday. "I want to go up and mix it up and try to win the thing."
In the final laps, much of the field bunched together in single file, riding high around the race track. Kenseth dropped down with Carl Edwards, Brad Keselowski and Joey Logano, but the move didn't work out, and they fell back.
"We needed about two more cars," Kenseth said. "I don't know if everybody just ... the guys from behind saw easy spots, so they stayed up on the top to hang out and just thought that was safer than actually trying to progress and end up getting shuffled back like I did.
"So, if I had to do it over, I would probably just ride up there. Just trying to make something happen."
It didn't work out for Logano, Edwards and Keselowski, either. Logano was 16th, while Edwards was 17th and Keselowski 29th.