DARLINGTON, S.C.— Chase Elliott missed his senior prom Friday, but wasn't too disappointed.

"I had a good date tonight, the 'Lady in Black,' can't forget about that," he said, smiling.

The 18-year-old son of NASCAR great Bill Elliott raced to his second straight Nationwide Series victory, moving from fifth to first on the final two laps Friday night.

Elliott broke through for his first series win last week at Texas when he passed Sprint Cup veteran Kevin Harvick.

At Darlington, Elliot moved past Sadler when the veteran got loose coming off Turn 2 on a restart two laps from the end.

Elliott drives for JR Motorsports, owned in part by Dale Earnhardt Jr. Earnhardt saw Bill Elliott at the Victory Lane celebration and asked how long it would be until Chase graduates — and gets to come to the race shop fulltime.

"He ain't even focusing on racing, he's in school," Earnhardt said. "Wait until he gets graduated, he's going to be really trouble for those other boys."

He's plenty trouble for Nationwide competitors right now. At 18 years, 4 months, 14 days, he became the youngest in the series to win twice and the youngest winner at Darlington.

"I don't know that we expected to come and win races at least this fast," Elliott said.

Elliott will graduate next month on May 17, when the Nationwide Series is in Iowa. He plans to test in Iowa on Friday, return to Georgia on Saturday for his graduation ceremonies before flying back to the track for night-time qualifying. "I want to make mom happy. I know she's going to be excited about that one," he said.

Sadler held on for second while Joe Gibbs Racing teammates Matt Kenseth and Kyle Busch were third and fourth.

Busch led by 1.5 seconds and was seemingly cruising to victory until Tanner Berryhill's spin forced a final restart and sent the field diving into the pits for a final shootout. Sadler moved from eighth to first after the stop by taking just two tires while Elliott was among the competitors who changed four tires.

Elliott charged hard on the restart and was right in back of Sadler on the final lap. When Sadler got loose — Sadler said the two didn't touch, although they surely came close — Elliott was able to move past him and take the checkered flag.

Elliott leads the point standings, topping JR Motorsports teammate Regan Smith by seven points.

"Man, that was crazy," Elliott said.

Then again, it's been a crazy time for latest Elliott to conquer the track "Too Tough To Tame." His father won here five times and earned the nickname "Million Dollar Bill" when his Southern 500 win earned him the Winston Million bonus in 1985.

Chase Elliott hadn't ever turned a lap at Darlington until Thursday and quickly gained a "Darlington stripe" — a rookie initiation — as he hit the track. But Elliott found his poise on the tricky track and raced among the more experienced drivers throughout the night.

Elliott led 52 of the 147 laps, second only to Busch's 84 laps led.

"Wait until he gets out of school," Earnhardt said.

Earnhardt believes Elliott has a composure and poise uncommon in young racers. "I'd like to think we're going to hold on to him," Earnhardt said. "But he's ahead of scale."

For much of the race, it appeared Busch would grab his third Darlington victory in as many Nationwide races.

Busch led by nearly a second and half heading into the late stages until Berryhill's incident sparked the last of seven caution periods.

But Busch couldn't make his way out of pile at the restart and settled for his sixth top-10 Nationwide finish in 10 career marks at Darlington.

Sadler, too, had hoped his crew's good work in the pits would steal a late victory. Instead, he picked up his third top-three finish in the past four Darlington events.