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.
The Tucson, Arizona, native made a late two-tire pit strategy work to his advantage after fending off teammate Larson in overtime to capture first victory at Vegas.
