Jimmie Johnson books NASCAR title shot with Martinsville win

Polesitter Martin Truex Jr, fresh from the heartbreak of missing out on the Round of 8 spot last time out at Talledega, held the lead until lap 182 of the 500, when he was passed by the Joe Gibbs Racing Toyota of Matt Kenseth.

Kenseth enjoyed a trouble-free stint of nearly 150 green flag laps but confusion reigned when the caution came out on lap 357 - right as a handful of leaders had opted to pit.

The unusual situation left crew chiefs and series bosses scratching their heads over who was leading when the caution came out, made more confusing by both Johnson and AJ Allmendinger running out of fuel.

But replays revealed that Allmendinger, who had been running at the tail end of the top 10 when the caution came out, inherited the race lead from the frontrunners pitting, effectively putting Kenseth a lap down.

Allmendinger was forced to pit for fuel while the pits were still closed, while Johnson managed to hold on long enough to wait for the pits to open before diving in.

That left Denny Hamlin and Kyle Busch, who were both exiting the pits when the caution fell, leading on the restart from Johnson, Jamie McMurray and Kenseth.

Johnson worked his way past the reigning champion within five laps, and passed Hamlin on lap 410, paying back an earlier incident where a touch from Hamlin caused left rear damage to the rear of Johnson's car.

Brad Keselowski enjoyed a late surge from eighth to second in the final 100 laps, coming home ahead of Hamlin and Kenseth.

Chase contenders Kyle Busch and Joey Logano both featured in the top 10 in fifth and ninth respectively, while Kevin Harvick and Kurt Busch both had days to forget in 20th and 22nd.

RESULT