Roush Fenway Racing teammate Matt Kenseth helped push Ragan to the win in the final lap.
Ragan in February was en route to a win at Daytona but was penalized for illegally changing his lane position.
He didn't falter Saturday, however, grabbing the lead just before a major crash involving Mark Martin and Brian Vickers during the first green-white-checkered attempt.
Kenseth gave Ragan pushing help in the final two-lap overtime restart and the teammates held off Joey Logano, Kasey Kahne and Kyle Busch on the final lap to secure the win for Ragan -- his first Sprint Cup title in 163 starts.
Kenseth finished second and Logano took the third spot.
Kahne and Busch rounded out the Top 5.