Busch emerged with the lead after a rapid-fire series of caution flags near the end, and he held off hard-charging Joey Logano to win by 0.740 seconds.
“My boys on pit road,” Busch said. “They’re amazing. I would do anything for them.”
Martin Truex Jr., racing with a broken right wrist, was third on the 1.54-mile trioval, followed by Kurt Busch and Ryan Newman.
The rest of the top 10: Jeff Gordon, Juan Pablo Montoya, Dale Earnhardt Jr., Kevin Harvick and Brian Vickers.
Kyle Busch was among three more drivers locking up their spot in the Chase heading to Richmond next weekend, where the 12-car field will be set for the playoff. He was joined by Harvick and Carl Edwards.
Points leader Jimmie Johnson, Clint Bowyer and Matt Kenseth had already claimed playoff berths before Atlanta.
Busch earned his 16th win of the year in NASCAR’s top three series. He has nine victories in Nationwide and three in trucks.
Logano had the fastest car on the track at the end of the race, but ran out of time to run down Busch.
“It’s just frustrating,” Logano said. “But in the grand scheme of things, it’s a big points day for us to get into the Chase going to Richmond. This helps us a lot. A win would’ve helped a lot more.”