However, despite a close battle with Chase Briscoe right to the end, the #8 driver could only manage second place.
It marked another near-miss for Busch, who has achieved five top-five finishes this season, including in the last three races where he finished fourth, second, and second, respectively.
Reacting to missing out on the playoffs after the race, Busch expressed huge disappointment, touching upon all of the times he very nearly made it happen this season.
"I wanted it last week. I wanted it this week. I wanted it in Atlanta. I wanted it in Vegas," Busch said live on air. "There's been a lot of opportunities,"
"Daytona 500 we were up front all day. I can count 'em at least on a hand. Maybe I need two hands to count opportunities that have slipped away."
Busch also reflected on falling short in the race at Darlington itself, explaining that he struggled in the turbulent air of Briscoe as he chased down the car in the lead on the final laps.
"When I made it through a few of those guys right there on the start, I thought we had a start to get there," Busch continued.
"I think I just needed him to have maybe three or four more laps, older tires for me to be able to break through the wake. Once I got within his air, I really didn't have enough to power through that, to get closer. I was kind of sliding already.
"Hate it for our guys, everybody on our team, everybody at RCR. They turned it around these last four, five weeks and we've run a lot better. That's been much improved, beneficial to our team and the organization."
Busch finished: "Maybe I am a washed-up old dog, but hopefully I can find a few more trophies."