"There's no better place to start than in the lead, right?" Keselowski said. "It feels like Round One of a heavyweight title bout. It's a 10-round bout, and Week One's done. We might have won the round, but didn't by any means knock 'em out."
Keselowski and his No. 2 Dodge got ahead of Johnson after a crucial pit cycle with about 35 laps remaining and led the final 26 laps in the 400-mile race. Johnson finished 3.171 seconds behind, and he said he thought Keselowski crossed a restraining line too early when exiting after that pit stop near the end.
The incident was reviewed and there was no infraction called, and Johnson never made much of a run at catching Keselowski during the final laps.
"He did cut up early. It did impede my progress," Johnson said. "But it didn't affect the outcome, I don't believe. The way he made quick work in traffic and stretched it out on me, I'm not sure I would have held him off. At the time it messed me up, but I don't think it played an outcome in the race."
All 12 of the Chase drivers finished in the top 18, with the exception of Jeff Gordon, who went into the wall with about 80 laps remaining. Gordon barely qualified for the Chase to begin with, and his championship hopes are already in serious jeopardy after his 35th-place showing Sunday.
It was Keselowski's fourth victory of the season. The Michigan driver leads Johnson by three points.
Denny Hamlin, the top seed coming in, fell all the way to 16th in the race while low on fuel at the end.
Sprint Cup standings
1. Keselowski 2,056
2. Johnson 2,053 -3
3. Stewart 2,048 -8
4. Hamlin 2,041 -15
5. Kahne 2,041 -15
6. Bowyer 2,041 -15
7. Earnhardt 2,039 -17
8. Biffle 2,037 -19
9. Truex 2,035 -21
10. Harvick 2,032 -24
11. Kenseth 2,030 -26
12. Gordon 2,009 -47