BROOKLYN, Mich. -- Matt Kenseth had little to say about how NASCAR's rules package affected his race at Michigan International Speedway.
"I didn't see much of the race, which was totally fine with me," he said. "We were up front the whole time."
Kenseth started in the lead, stayed there for most of the day and finished with his third Sprint Cup victory of the season Sunday, beating Kevin Harvick by 1.7 seconds.
It was the second race under NASCAR's high-drag aerodynamic package, which was also in place at Indianapolis last month in an effort to improve passing. At Michigan, Kenseth won while leading 146 of 200 laps, so whatever excitement there was occurred further back in the pack.
"Cars could really, at the end of the straightaway, gain on others, two or three car lengths," said Jason Ratcliff, Kenseth's crew chief. "But they just couldn't do much once they got there and they got down in the corner. They were kind of helpless. On the restarts, it got exciting. ... I'd say eighth place back, it was fun to watch. Like Matt said, I'm glad he was watching it in the rearview mirror."
Kenseth led 73 percent of the laps Sunday, the highest percentage by anyone in a Cup race this year. He had led only 147 laps all season before dominating this 400-mile race in his No. 20 Toyota.
It was his 34th career victory, and Joe Gibbs Racing has won five of the past six Cup races -- two by Kenseth and three by Kyle Busch.
"You really need to enjoy it, because about 10 races back, we were struggling, trying to get there," Gibbs said. "You just hope now that we'll be able to hold some momentum here and head into the Chase, but it's very hard to do. In pro sports, it can come and go in a week."
Martin Truex Jr. finished behind Harvick in third. Austin Dillon, who was sent to the back at the beginning of the race because of an engine change, managed a fourth-place showing, and Busch took another step toward wrapping up a spot in the Chase with an 11th-place run in his backup car.
Kenseth led for the first 22 laps, and there were 16 lead changes after that. Kenseth had a comfortable lead before a caution with 17 laps remaining tightened things up, but he had little trouble holding off Harvick after the restart.
Clint Bowyer's Chase chances look more tenuous after he went into the wall Sunday and finished 41st. He is now 15th in the standings.
Busch came into the race in 30th place, needing to avoid a major mistake because although he has four wins in 2015, a top-30 ranking is required for entry into the Chase. Busch wrecked his car in practice Saturday and had to start the race from the back, but he had a solid, uneventful day, even leading for a couple stretches.
He is now 29th in the standings, 23 points ahead of 31st-place Cole Whitt.
"It was a success," Busch said. "It wasn't what we wanted. We had a really, really fast car yesterday, but I screwed up and wrecked that car. It was a winning car, maybe not the winning car. But congratulations to our teammate Matt Kenseth and the 20 bunch. It's really good times for Joe Gibbs Racing right now."
Harvick remained atop the standings and now leads Joey Logano, who finished seventh, by 48 points.
The rules package caused some concerns over the heat, and NASCAR mandated a dual outlet duct be used on the right-side window to help with ventilation and keep the cockpit from being too hot for the drivers. NBC Sports showed a reading of over 150 degrees in the cockpit of Casey Mears' car -- and that was during the first quarter of the race.
"You knew it was going to be a little bit hotter. We prepared for that," Kenseth said. "Started hydrating a couple days ago and drinking a lot of Gatorade and tried to eat right and get some sleep. ... It really wasn't bad. Yeah, it was hot, but I've been a lot hotter."