SPARTA, Ky. -- Cole Custer became the first rookie winner in the NASCAR Cup Series in nearly four years, surging to the lead in a four-wide, final-lap scramble Sunday at Kentucky Speedway.

Kevin Harvick and Martin Truex Jr. were dueling side by side for the lead on the Lap 265 final restart when Custer -- with a push from Matt DiBenedetto on the outside in the backstretch -- made his move in the No. 41 Stewart-Haas Racing Ford. As the leaders bunched in Turn 1, Custer slid ahead and outlasted Truex's Toyota.

"I knew I just had to get to the top," said Custer, who led twice for five laps -- the first Cup laps led of his young career. "The top rolled pretty good and once I got past and I was like in third I was like, 'I've just got to take a shot and do whatever I can here.'

"And it ended up the 4 [Harvick] and the 19 [Truex] got together a little bit and I was able to take advantage of it."

Though Custer raced to a Kentucky win last July in the Xfinity Series, he and other drivers entered Sunday without a chance to practice or qualify.

Matt Kenseth's Turn 4 spin forced the final caution and created the opportunity for Custer's victory. Kenseth finished 25th after starting from the back with Truex as both failed two prerace inspections.

The victory was the first by a series rookie since Chris Buescher won at Pocono on Aug. 1, 2016. Making his 20th series start, the 22-year-old Custer celebrated with a frontstretch burnout as his crew happily ran to greet him.

DiBenedetto was third, and Harvick fourth -- both in Fords. Kurt Busch, the winner last year, was fifth.

Aric Almirola made his case at the start, pushing pole-sitter Kyle Busch forward from the outside and chasing in the early laps before taking over nine laps later and threatening to run away from it. Almirola led 128 of the first 137 laps -- nearly 40 more than he has led all season.

Ryan Blaney and DiBenedetto took their turns in front before Keselowski inherited the lead on pit road during green-flag pit cycles. That didn't last long as Truex quickly stalked him on the last-stage restart and took over on Lap 181 in hopes of his third Kentucky win in four years. Truex settled for watching Custer take the win.

"The 41 [Custer] just came with a big head of steam and there was no way I was going to be able to block that," Truex said. "He was just in the right place at the right time, I guess."