DARLINGTON, S.C. — Martin Truex took the lead with 28 laps to go and held off Kevin Harvick on the final restart to win the Southern 500 on Sunday night.Truex started the summer season by leading an astounding 588 of 600 miles to win at Charlotte on Memorial Day weekend. He closed the season by outracing Harvick on Labor Day weekend for his second crown jewel win of the season and his first Sprint Cup victory at the old, egg-shaped oval.Truex pulled to the inside wall to greet his crew, then took off for some celebration donuts at "The Track Too Tough To Tame."Truex stamped himself as a contender to be reckoned with when the Chase for the Championship starts in two weeks."We're hungry. We're working hard," Truex said. "This is just the beginning for us, I think."Harvick had the dominant car — he led 214 of 367 laps — but this run was cut short by slow pit stops. At one point, Harvick fell 11 spots from first to 12th after a 16.6-second stop. He battled back but could not catch Truex.Last week's winner at Michigan, Kyle Larson, finished third and Denny Hamlin was fourth. Joey Logano was fifth, followed by Matt Kenseth, Kasey Kahne, Ryan Newman, Brad Keselowski and Chase Elliott.Truex moved past leader Newman on Lap 339 to take the lead and stayed in front on a final restart to win another of what was once considered one of NASCAR's most-prized races."This is unbelievable," Truex said. "I've always loved this racetrack. I've led a lot of laps here, and I feel like something always happens. I'm proud to get to Victory Lane with this group."It's the second time in the past six Southern 500s that single-car Furniture Row Racing wound up in Victory Lane. Regan Smith stunned the Sprint Cup garage in 2011 with his win here.Harvick could not overcome his shoddy pit showing and was frustrated with his team."We have championship cars and we're just mediocre on pit road. It's been that way for a few years," he said.Jimmie Johnson had troubles at a track where he has won three times.He was called for a pass-through penalty after his crew made a modification on pit road NASCAR didn't like, then fell two laps down. On Lap 214, Johnson spun out and slid into the inside wall. His crew brought the No. 48 Hendrick Motorsports machine behind the wall for a 33rd-place finish.It was Johnson's ninth finish outside the top 10 in his past 12 races — not the form his team hoped to have in chasing a seventh Sprint Cup title.Three-time series champ Tony Stewart, making his final run at Darlington before he retires, was trying to get past the lapped car Brian Scott just past the midway point.When that didn't work at first, Stewart looked like he nudged Scott's bumper and sent him spinning. Scott thought Stewart was mad at him and ran into him on purpose. "I'm not sure if he thought I was trying to hold him up. I wasn't," Scott said.The move also caught NASCAR's interest. Officials called Stewart and crew chief Mike Bugarewicz to their hauler at the end.When told of NASCAR's demand, Stewart said, "Hey man, made it 25 races, I'd say that's pretty good."Stewart's race ended early when an overheating engine expired 49 laps from the end. He finished 35th.The race featured throwback paint schemes for almost the entire field, appropriate at a venue where NASCAR first raced in 1950. Stewart drove the red-and-gold Coca-Cola car patterned like the one Bobby Allison steered to victory at the Southern 500 in 1971 and '72.