Earnhardt Jr did eventually get by Harvick for second spot on lap 333, four laps after Hamlin took the lead and had it not been for a lap 345 caution period for Robby Gordon's turn one accident, the driver of the #11 Joe Gibbs Racing Chevrolet may have been away to victory despite having to race with 19 stitches in his left hand.
As it was, all the leaders took the opportunity to take on fresh rubber for the final time with Hamlin losing several places and Kyle Busch jumping into top spot in the #5 Hendrick Chevrolet.
The green flag waved with 49 laps to go and it took Earnhardt Jr less than five tours to work his way around Busch and into the lead. Harvick followed suit a handful of laps later and with 30 to go it looked like being a straight fight between the #8 and the #29. However Harvick didn't seem to have the same edge that he possessed earlier in the evening and couldn't challenge the fleeing Earnhardt Jr. With 15 laps to go Hamlin swept through to grab second spot leaving Harvick a disconsolate third on a night where he led 272 of 400 laps.
Even with two caution periods in the final 15 laps nobody could get a run on Earnhardt Jr, who celebrated his win in fine style with the best burnout of the season by far and moves up two positions in the points table to sixth in the process.
Hamlin was equally delighted with second place, his best result to date, although Harvick was less thrilled with third, even though he moves up to fifth in the championship.
Biffle came home fourth after a fine recovery drive that saw him pass five cars in the final ten laps including Kyle Busch and Tony Stewart. Although fourth spot doesn't get the driver of the #16 Roush Ford back within 400 points of the series lead, it at least marks something of an upturn in fortunes for the hard-luck driver of the season thus far.
Kyle Busch took fifth position in a race where he didn't resort to any typical short track nudging tactics and showed to his rivals that lessons are being learned week in, week out in the cockpit of the #5 Hendrick Chevrolet.
At times, defending Nextel Cup Champion Stewart looked like he had a car that could contend for the win but on a night where three of the top six drivers in the championship at the start of the race suffered problems and with points leader Jimmie Johnson also struggling, Stewart seemed content to settle for a sixth place finish that moves him up one place to second in points, just 55 markers behind Johnson.
Johnson rallied to a twelfth place finish on a night where he ran in the lower reaches of the top 30 most of the way and was able to preserve his points lead thanks to a late surge into the top 20 and problems for several of his nearest rivals.
Matt Kenseth, second in points at the start of the night, lost nearly 50 laps in the pits after running over his own brake rotor and rupturing his oil tank while Jeff Gordon also lost many laps in the pits with a mystery engine problem that would eventually lead to his retirement. Defending Crown Royal 400 winner Kasey Kahne also lost several laps with a faulty plug wire and finished 34th, four places ahead of Kenseth and six ahead of Gordon.