Ross Chastain celebrates in Victory Lane after winning a NASCAR Cup Series at Kansas Speedway on Sundayin Kansas City, Kan. Colin E. Braley/Associated Press

KANSAS CITY, Kan. — Ross Chastain finally got to smash a watermelon for the first time this season Sunday at Kansas Speedway.

Smashed the hopes of a bunch of playoff drivers trying to earn an automatic berth in the next round, too.

The seventh-generation watermelon farmer took the lead from Martin Truex Jr. on a restart with 20 laps to go, then held off title contender William Byron the rest of the way to the finish line. It was the first win for Chastain since last year’s finale at Phoenix, when he also played a bit of a spoiler on the day that the NASCAR Cup Series crowned its champion.

“We haven’t gone anywhere. We keep showing up,” said Chastain, who barely missed out on qualifying for the playoffs. “It’s not easy when you’re failing or struggling at something, and you just can’t get to where you want to get to.”

The retiring Truex, who was eliminated from the playoffs last week, finished third in what was likely his final Kansas race.

He was leading when Carson Hocevar brought out the final caution of a wreck-filled day. Truex picked the top on the restart, and Chastain opted for the bottom, and it was the No. 1 car from Trackhouse Racing that got the big push to the front.

“It’s pretty deflating when you don’t make the playoffs, and we knew the last couple of races of the regular season, we were right on that cut line,” said Chastain’s crew chief, Phil Surgen. “But there’s no give-up here. We’re not laying down.”

Byron’s second-place run was the best among the 12 drivers going on to the second round of the playoffs. And while the win would have locked him into the next round of the playoffs with unpredictable Talladega up next, the result was enough to move the No. 24 car to the top spot in the playoff points standings.

“You’re so close, and going to Talladega, you know what that is,” Byron said. “But proud of the effort.”

Ryan Blaney had a loose left wheel in the final stage but rallied to finish fourth, giving the defending champ’s postseason hopes a big boost. Ty Gibbs was fifth, followed by four more playoff contenders: Alex Bowman was sixth, pole sitter Christopher Bell recovered from a couple of scrapes with the wall to finish seventh, Denny Hamlin salvaged an eighth-place run after trouble on pit road, and Chase Elliott was ninth after starting at the rear of the field due to an engine change.

“Considering yesterday and starting last and everything, it could have been a lot worse,” Elliott said. “But I’m always on the side of the fence where our car was good enough. I felt like (the results) could have been a lot better, but we’ll take it.”

Kyle Busch looked like he might finally extend his streak to 20 seasons with a Cup Series win when he passed Chastain with 64 laps to go. But cycling back to the front after pit stops, Busch was trying to squeeze by Chase Briscoe as the latter fought to stay on the lead lap. Busch ended up hitting the wall and skidding down the back stretch with 30 laps to go.

He wound up 19th, extending his winless streak to 51 races dating to last year in St. Louis.

“I guess I got in too big of a hurry,” Busch said. “I mean, I’m numb. I don’t know what to do.”

Kyle Larson had perhaps the longest day of anyone. The winner last week at Bristol had a right rear go down 18 laps into the race, sending him into the wall. The damage appeared to be minimal, and his Hendrick Motorsports crew kept working at it the rest of the race. But he still finished 26th, just behind fellow playoff drivers Briscoe and Tyler Reddick.

Austin Cindric had to pit twice at the end of Stage 1 because of a loose wheel, but he was back in contention when his left rear went down near the end of Stage 2, sending him spinning down the back stretch. He finished four laps down in 34th.

“That is unacceptable for the position we are in, and especially with the speed we’ve had in the car,” Cindric said. “I’m pretty bummed about all that. I think the next two weeks are weeks we can go have great races, but we definitely won’t be able to get this one back. It makes our goals a little more clear going into Talladega and the Roval (at Charlotte).”

POINTS PICTURE

Blaney and Bell are six points behind Byron in the playoff standings, and Larson another 10 points back. Joey Logano is in the eighth and final spot above the cutoff, four points ahead of Reddick and 14 ahead of Daniel Suarez. Briscoe and Cindric are the other drivers in peril with two races left before the next cutoff.