It was Johnson's second victory of the season and the fourth straight for a Hendrick Motorsports driver.
The race featured a 12-car crash in the ninth lap -- the biggest so far in the 2012 Sprint Cup season. It was precipitated when Tony Stewart made contact with Landon Cassill. Both drivers spun around, as did Regan Smith, triggering a chain reaction on the backstretch.
There were no injuries in the mishap, which delayed the race for 20 minutes.
Greg Biffle remained the points leader despite an 11th-place finish.