The two-time Cup champion from Las Vegas, Nevada, benefitted from a final lap collision involving Tyler Reddick and Chase Briscoe to become the ninth different competitor to reach 60 victories in NASCAR's premier series.
The reigning NASCAR Camping World Truck Series champion persevered on a five-lap dash to the finish to cap off a dominant run with his first victory of the season and on Bristol's dirt course.
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 2018 NASCAR Cup Series champion will be making a one-race return to the Truck Series for David Gilliland Racing next weekend on Bristol's dirt layout.
The Alva, Florida, native bumped AJ Allmendinger and Alex Bowman out of the racing groove on the final lap to earn the first win in NASCAR's premier series for himself and Trackhouse Racing in Austin.
