DARLINGTON, S.C. (Sporting News NASCAR News Service) -- Maybe Matt Kenseth's luck has turned again.

On Friday afternoon, Kenseth was the surprise pole winner for Saturday's Southern 500 Sprint Cup race at Darlington Raceway.

On Friday night, he completed the daily double with a victory in the Diamond Hill Plywood 200 Nationwide Series race at the 1.366-mile egg-shaped track, after misfortune struck the dominant car of Kyle Busch in the closing circuits.

Kenseth inherited the lead when Busch was forced to pit under yellow with a cut right-rear tire and won the race under the record-tying 10th caution period of the night, when Morgan Shepherd spun moments after a restart for a green-white-checkered-flag finish that took the race six laps beyond its scheduled 147 laps.

The victory was Kenseth's first of the season, his third at Darlington and his 25th in the series, fifth best all-time. Jason Leffler came home second, followed by Carl Edwards and rookie Erik Darnell, who posted his first top-five finish in his third start in the series. Fellow rookie Justin Allgaier ran fifth.

"Today couldn't have gone any better than it did, that's for sure," said Kenseth, who won the first two Cup races of the season before his fortunes soured and a series of miscues and mishaps dropped him to 12th in the standings. "Like I said earlier, it's all really about the cars and the people that work on them and your pit stops and all that.

"I can't go fast with slow cars, which I proved over the last couple months. It feels good to be able to win one of these things… On the Cup side, it feels good to make changes today, and the car actually reacted to it and seemed to drive a lot better than our stuff has lately, so it's been a good day for us. Hopefully, that will continue (Saturday)."

With Busch finishing 16th, Edwards trimmed the Joe Gibbs Racing driver's advantage in the series standings to 37 points.

Busch, who led a race-high 143 laps, was two circuits away from victory when a wreck on the backstretch involving Scott Lagasse Jr. and Joe Nemechek brought out the ninth caution and set up the green-white-checkered-flag finish. Busch ran over debris from the wreck.

Busch's right rear tire sustained a cut to the inside sidewall. The tire likely would not have survived the restart, and Busch and crew chief Jason Ratliff made the prudent call to pit and change tires.

Notes: Friday's Nationwide qualifying session was rained out, and the starting field was set according to owner points. Busch started from the pole and Kenseth from the sixth spot… Brad Keselowski survived three spins, the first on the initial lap of the race, to finish 11th… Ryan Newman drove Kevin Harvick's No. 33 Chevrolet to a sixth-place finish. That car now leads Busch's JGR Toyota by seven points in the owners' standings.