The Trackhouse Racing Chevrolet driver took the lead after the final set of green flag pitstops, and narrowly avoided a 23-car pileup in the closing laps. Daytona 500 glory was in sight, but the battle wasn't over just yet.
William Byron (Hendrick Chevrolet) took over at the front when racing resumed after a brief red flag with four of the 200 laps remaining, but Chastain mounted a massive charge coming to the white flag.
With Alex Bowman (Hendrick) pushing Chastain, Byron moved up the track to block. At the same, Austin Cindric and Corey LaJoie got crossed up on the inside lane.
Chastain saw an opportunity and tried to shoot the gap up the middle but there just wasn't enough room for all three cars, with Chastain and Cindric sent spinning into the infield as the final lap began. The caution flag immediately followed and Byron was declared the race winner.
Despite the disappointment of being classified 21st after leading 14 of the final 20 laps, and missing out on a fifth Cup Series victory, Chastain confirmed he was satisfied with the showing.
"I am [satisfied]," said Chastain. "To learn the fuel saving game and really get aggressive and match these guys, so that we can pit when we need to...
"I have burned up too much fuel in the past couple of races and to put ourselves in position on the final pitstop to come out with the lead, cover the other OEM [Ford] when they caught up to us, and just work with some legends of the sport, and have control over the race there at the end.
"I really do feel content. It’s weird to say it, but we did everything right."
Looking at the race-ending incident, Chastain was just happy to have had a shot at NASCAR's biggest prize, but accepted the move had been too optimistic.
"When you crash, I think so," he said. "Happy for William and Chevy and General Motors to win.
"It was really awesome for us to control some of the cycles, the green flag pit cycles, and kicked their butts. So that was really cool and then to have a bunch of Chevys left there at the end there made me feel good.
"It was cool Alex [Bowman] pushed me there at the end and I felt like there was minimal chance that a Chevy wasn’t going to win and one of them got it done. But yeah, too aggressive is when I don’t finish."
Penske Ford driver Cindric, seeking his first win since winning the 2022 Daytona 500, called the accident "a really unfortunate end" as he eventually was classified 22nd.
He also took issue with LaJoie, who attempted to go three wide and caused the inside line to lose momentum in the run to the white flag.
"We were really in great position with the outside lane breaking up and kind of one-on-one with the 24 [Byron] with the whole pack behind, so you can’t really ask for anything else other than that out of myself and the team," Cindric said. "It just sucks a little bit.
"Corey [LaJoie] finished fourth, so congrats. He tried to fit a car where there wasn’t a car and just continued to push through my left-rear until I wrecked.
"I understand trying to shuck me out or put up an opportunity because I was in probably the best spot possible coming to the white, but I’m in the care centre and I don’t even know where I finished, so it really sucks but that’s racing."
