Denny Hamlin started on pole at Charlotte, but faded quickly and was not much of a factor until a big wreck on an overtime restart left Hamlin with the lead. Hamlin battled Kyle Busch in the second overtime and edged his teammate by 0.014 seconds.
Kurt Busch, the 2004 Cup Series champion from Las Vegas, Nevada, led a race-high 116 of 267 to notch his first victory in the Heartland State and his first driving for 23XI Racing.
The 29-year-old Chastain from Alva, Florida, rallied from an early pit road speeding penalty to overtake Erik Jones on the final lap through the tri-oval to claim his second career win in NASCAR's premier series.
The 24-year-old Byron from Charlotte, North Carolina, led a race-high 212 of 403 and fended off Joey Logano during an overtime shootout to repeat as a Cup winner at the Paperclip-shaped short track.
The three-time Daytona 500 champion from Chesterfield, Virginia, fended off Kevin Harvick in the final five laps to notch a breakthrough victory at his home track.