ATLANTIC CITY, N.J. — Without a helmet or strapped in a seat, Kevin Harvick should have been far more comfortable with a beer in hand and a view from a suite.

But nerves hit the NASCAR star much worse than they get him before any green flag drops. Harvick had no control of the outcome with his KHI client Donald “Cowboy” Cerrone set to fight in the main event of Wednesday’s UFC card.

“I’m way more nervous than I would be sitting in the seat of my car and driving myself,” he said.

Everything turned out just fine for Harvick and Cerrone (24-6-0), who made quick work of Jim Miller with a second-round knockout in a lightweight bout.

Cerrone’s kick with his right foot nailed Miller flush in the head and sent the New Jersey native to the canvas. Cerrone backed off when Miller (24-5-0) went down in a heap right in front of Harvick.

Cerrone won his fourth straight fight when it was stopped at 3:31 of the second, the thwack of the front of his foot to Miller’s skull heard up in the cheap seats.

“I saw his body was getting tired and I saw him drop his hands,” Cerrone said. “I knew I could go for the finish and I went for it.”

Harvick attended the Revel Casino Hotel card to watch Cerrone headline UFC’s latest card in New Jersey. Cerrone is one of a handful of athletes and entertainers Harvick manages under the Kevin Harvick Inc. banner. They met at a Tapout sponsorship event and Cerrone soon attended a NASCAR race. The duo hit it off and Harvick and Cerrone reached a representation deal in June 2013.

Cerrone was at Daytona International Speedway in February to present Harvick, a UFC fan, with an authentic championship belt.

Both NASCAR and UFC experienced boom periods that saw the sports soar in popularity and move away from a niche fan base and into the mainstream.

NASCAR and UFC both have TV deals with Fox — not bad considering mixed martial arts is still banned in New York.

“It’s a very blue collar, everyday type of fighter that goes into the ring,” Harvick said. “Most of these guys came from nothing and built themselves into having a shot through the fight world. It’s kind of a lot like a lot of us drivers have done on the NASCAR side of it.”

Harvick, a two-time Sprint Cup winner this season, used his connections to land sponsorship deals for his clients. Greenlee Textron, Budweiser and E-Z-Go had a spot on Cerrone’s trunks for the bout on Fox Sports 1.

“The cross promotion has been great,” Harvick said. “Having Cowboy as the main event is great for the NASCAR fans and the UFC fans. It’s a pretty common landing ground.”

Before they traded up for cage-side seats for the main event, Harvick shared a suite with Los Angeles Kings forward Jeff Carter. When the former Philadelphia Flyers star walked into the suite, Harvick said: “The Flyers traded their whole team so they could watch the Kings win the Stanley Cup.”

“Two of `em,” said a grinning Carter, missing his upper two front teeth.

Some of the fighters on the card ended up in worse shape.