SPARTA, Ky. – Entering Sunday’s Quaker State 400 presented by Walmart, rookie Cole Custer had never led a lap in his NASCAR Cup Series career, but that didn’t stop him from leaving Kentucky Speedway with the trophy.

Custer used a stunning four-wide pass on the final lap at the 1.5-mile, D-shaped oval to steal the win from the race’s two dominant drivers, Kevin Harvick and Martin Truex Jr, during an exhilarating green-white-checkered finish.

The two-lap sprint was set up by a Matt Kenseth spin in turn four that forced the yellow with seven to go, setting up Harvick as the leader after he and Truex were racing side by side for the top spot moments earlier.

When the green flag waved on lap 266, Custer was sixth, but got a huge shove from behind by Matt DiBenedetto to surge down the backstretch and emerge in fourth exiting the fourth corner.

Meanwhile, Harvick and Truex – still side by side for the top spot – made contact in turn three that slowed their momentum and brought Ryan Blaney into the mix on the very bottom of the race track.

As Blaney cut to the low lane, Custer squeezed to Truex’s outside, making it four-wide across the stripe at the white flag. Moments later, Blaney passed over a drain on the apron that caused his car to break loose, shooting up the track and into the side of Harvick’s Ford.

That caused Truex to swerve momentarily as an evasive maneuver, giving Custer the ability to break free of the trio underneath him and lead uncontested down the backstretch.

From there, Custer drove home to his first win at NASCAR’s top level in just his 20th career start, beating Truex to the finish line by .271 seconds.

Custer became the first rookie to win a Cup Series race in Kentucky Speedway history and the first Cup Series rookie to win in the series since Chris Buescher at Pennsylvania’s Pocono Raceway in 2016.

“We were so good all day. Our car was so good,” said a jubilant Custer. “Obviously, it wasn’t the easiest track to pass on, so we were kind of stuck back there, but that was the best car I’ve driven in my life. Everybody at SHR brought an unbelievable car. Mike (Shiplett, crew chief) and Davin (Restivo, engineer) on the box were unbelievable. Gene (Haas), I can’t stress enough how thankful I am for him taking a shot at me.

“It definitely was not the start of the year that we wanted,” Custer added. “We were way off at some places, but this was an unbelievable car. We put it all together and I just can’t thank everybody enough.”

With his breakthrough win, Custer not only catapulted himself into the playoffs, he also locked himself into Wednesday night’s $1 million NASCAR All-Star Race at Bristol (Tenn.) Motor Speedway.

“This (season) has not been easy. You have to adapt as much as you can, and I think we’ve gotten better and better at that,” he added. “It’s just unbelievable. I didn’t think that we were coming here to win. Now, we’ve won … we’re going to be in the All-Star Race. I don’t even have to run the Open!

“Hopefully, I make it to Bristol.”

After the race, Truex lamented the slightest of contact with Harvick on the first lap of the green-white-checkered that he noted ultimately dropped the race win into Custer’s hands.

Still, however, he offered enthusiasm at the excitement of the final three-mile stretch.

“That was fun. I can’t say enough about the guys on this Auto Owners Camry and everybody back at JGR. We went to work this week and tried to kind of get back what we used to do here, so hats off to the guys and James (Small, crew chief) and everybody,” Truex said. “At the end there, we were just a bit unlucky … losing the lead to Blaney on that first restart by a couple thousandths, and then again to the 4 (Harvick) when the caution came out. We were side-by-side. That’s kind of the way these things go sometimes.

“I’m really proud of the effort; we had a super-fast race car and I feel like we’re back in the game now.”

DiBenedetto came from eighth with two to go to finish third, while Harvick hung on for fourth despite heavy damage from the contact with Blaney heading for turn one on the final lap.

“We got a couple good restarts and were in position to win. Made it through turns one and two, and then Martin just misjudged on the backstretch and kind of got into the back of us,” explained Harvick. “I had to check up and next thing I knew, I was four-wide on the front-straightaway and then the 12 hit the drain and went back up the race track.

“Everybody at Stewart-Haas Racing is continuing to bring great cars, though, and congratulations to Cole Custer,” added Harvick of his teammate. “Obviously, last week he was a big part of our win, and to get to victory lane in your rookie year is a big deal. Really happy for Gene (Haas) and everybody at Haas Automation … and especially for Cole, because he works really hard.”

Kurt Busch filled out the top five, followed by Blaney, Christopher Bell, Aric Almirola, Brad Keselowski and Tyler Reddick. Almirola won stage one and led a race high 128 laps.

The NASCAR Cup Series next visits Bristol (Tenn.) Motor Speedway Wednesday night for the NASCAR All-Star Race.

Kyle Larson, now racing sprint cars and midgets full time, won the event one year ago.

To view complete race results, advance to the next page.