Keselowski overtook Kevin Harvick with 21 laps to go in Saturday’s F.W. Webb 200 when Harvick’s No. 33 ran into lapped traffic, specifically the No. 24 driven by Amber Cope, the 28-year-old niece of Derrick Cope, who won the 1990 Daytona 500.

Forced to slow down or risk running into the back of Cope’s car, Harvick watched helplessly as Keselowski’s No. 22 roared past on the outside. Keselowski took it from there, earning his second series win of the season, 19th of his career, but first in five starts at NHMS.

“It slowed down his momentum,” Keselowski said of the fortunate pass on Lap 179. “And from there it’s just a matter of trying to capitalize on it. It’s just lapped traffic, and the battles that come with it.”

Would his car have been strong enough to catch Harvick without the fortunate break?

“I don’t know, there’s no way of really knowing that. The odds were probably not in my favor,” Keselowski said. “But you catch good breaks and bad breaks. That’s what makes racing special.”

Harvick did little to hide his feelings.

“The 24 [Cope], every time you come to her, she doesn’t know whether she’s going high or low. It looked like she went up, so I committed to the bottom, but she went down,” Harvick said. “It’s somebody who shouldn’t be on the racetrack, who has no idea what they’re doing in a racecar.

“She wants to be Danica Patrick, but she can’t hold her helmet.”

Keselowski and Harvick had the two dominant cars in the race, combining to lead 155 of the 200 laps. Keselowski, the pole-sitter, led for the first 38 laps, only losing it when the first caution came out and he chose to take four tires on the ensuing pit stop, while others took two and didn’t need as much time.

Leading the race in big chunks — 38 laps, then 41, 30, and the final 21 — Keselowski seemed to have the horsepower to end his NHMS drought. But when Harvick took the lead after a restart on Lap 155, it looked like Keselowski would need a little lady luck, which came soon enough.

“I’ve had great runs here in the past, but we haven’t been able to close the deal,” Keselowski said. “It feels good to finally come here and close the deal, be able to not only be the fastest qualifier but also to win the race.”

Austin Dillon was third, followed by Sam Hornish Jr., and Ricky Stenhouse Jr.

Kyle Busch was gunning for his fourth straight series win at NHMS, and qualified fifth fastest (he’ll start from the pole in Sunday’s race). But he quickly encountered trouble with his fuel gauge, and when he came in during the first round of pit stops during a caution on Lap 38, he stayed in. The carburetor was changed, but when Busch finally got back out, his car didn’t respond.

Busch brought the car into the garage not long after green flag racing resumed. The crew installed a completely new fuel cell, and he was able to return to the track after losing 28 laps. He was never a factor, and finished 28th.

Series points leader Elliott Sadler started seventh, ran for most of the race inside the top 10, and finished seventh. He increased his points advantage over Dillon, and now leads by 3.

Patrick, with just one top-10 finish this season, started 18th, got as high as 10th, but was responsible for the race’s fourth and final caution when her car made contact with the No. 81 of Jason Bowles. Patrick spun out after the bump, but kept racing. She finished 14th.

Cope finished 26th. By then, her impact on the race had already been made.

Michael Whitmer can be reached at mwhitmer@globe.com. Follow him on Twitter @GlobeWhitmer.