The Tucson, Arizona, native emerged with the lead under the final 100 laps following a stellar service from his pit crew to tame his first Monster Mile victory.
Martin Truex Jr. swept Stages 1 and 2 at Darlington and held off Kyle Larson in the closing laps of the final stage to take the win, his third of the year.
The 2018 Cup champion stormed to the front in the late stages and outlasted the field in overtime to win the inaugural Cup event on the Bristol Dirt Course.
The 27-year-old native from High Point, North Carolina, spoiled Kyle Larson's dominating run to grab his first Cup victory of the 2021 season at Atlanta.
