SPARTA, Ky. (AP) — Austin Dillon lived up to the legend of the No. 3 car, then had his victory called into question Friday night.

No one had regularly driven the No. 3 car since Dale Earnhardt's death on the track at the 2001 Daytona 500. On a warm night in the Bluegrass state, Dillon routed the field, only to have the car fail its postrace inspection.

Dillon took the lead early and was on top for 192 of the 200 laps to win the NASCAR Nationwide Series race at Kentucky Speedway.

"I love running the 3," Dillon said. "It pressures me every week to give 110 (percent)."

Roughly an hour after the trip to victory lane, the No. 3 failed the inspection for being too low in the rear. NASCAR announced it would issue a ruling early next week.

Reached at the garage, Dillon's crew chief, Danny Stockman, wiped sweat from his forehead as he left a meeting with officials.

"We've had an issue before. We addressed it in a meeting," Stockman said. "It should have been addressed. That's the only comment I've got."

A similar situation took place earlier this season at Iowa where a car also failed a postrace inspection. The crew chief was fined $10,000 and six points were subtracted from the team.

The No. 3, of course, was driven to fame by Earnhardt, who raced for the Richard Childress team. Childress is Dillon's grandfather and also his team owner.

As Dillon was clinching the win, his grandfather said over the radio, "Dale would have been proud of that."

He added, "I couldn't be prouder as a grandfather and a team owner. I know Dale's looking down smiling to see that 3 win tonight."

It was the first Nationwide victory for Dillon, a rookie who captured the Truck Series title a year ago.

"It takes a little off your back when you get that first win," Dillon said with a broad smile while wearing a white cowboy hat with his black — what else? — driving suit.

Dillon had asked to drive the No. 3 car, which has made it's only appearances since Earnhardt's death with Dillon behind the wheel in the Truck Series — and with Dale Earnhardt Jr. in three other races, including a victory at Daytona in the Nationwide event two years ago.

Dillon has marked himself as one of the fastest rising drivers in the sport. Childress was careful in his reply when asked if he might ever back another team in the Sprint Cup — the big leagues of stock car racing — in car No. 3.

"I don't plan on running the 3. Dale made that stylized 3 famous," he said. Then, with a grin, he added, "We don't have any intention of running that (stylized 3) in the Cup. That leaves an opening, doesn't it?"

Dillon, a 22-year-old native of Lewisville, N.C., also tentatively took over the series lead with the victory. He came into the night just a point back of leader Elliott Sadler after seven top-five finishes: five fifths and two fourths.

Sprint Cup driver Kurt Busch was a distant second, 9.828 seconds back. Third went to another Cup driver and the No. 2 qualifier, Kevin Harvick, who was followed by Michael Annett and Justin Allgaier.

"Austin Dillon, he was just in his own zip code," Busch said. "Congratulations to him. It's been nice to see him develop."

Busch said he thought he had a car that could run down the pole-sitter, but that charge never materialized.

"He was just too strong tonight," Busch said. "He just had that car dialed in. There was nothing we could do."

Harvick, who took over Earnhardt's Sprint Cup ride after Earnhardt's death, said he admired what he had seen out of the young Dillon.

"I'm proud to see Austin and those guys get their first win," he said. "He works hard to make himself better and he's a good kid."

Asked what he thought of seeing the No. 3 car returning to victory lane, Harvick said, "I'm sure it's important to Richard and his family. Richard started with the 3. He and Dale had a lot of success with the 3. So I'm sure it's important to them."

The race was contested in ideal conditions after gusting winds earlier delayed qualifying for the Cup Series.

Rounding out the top 10 were Sam Hornish Jr., Brad Keselowski, Ricky Stenhouse Jr., Sadler and James Buescher, who won the Truck Series race on Thursday night. Keselowski won the Nationwide event a year ago in Kentucky.

The tributes to Dillon came from all quarters after the race.

"I envy his first win," said Danica Patrick, who finished 12th.

Childress beamed as he spoke of his relationship with Earnhardt and what might be for his grandson.

"Austin has come so far," he said. "To watch him tonight, he's so patient. You'd think he's been racing a long time."