Truex Jnr nabbed victory in Stage 2 as a result of then-leader Joey Logano getting delayed by a backmarker.
The #19 Toyota remained in the lead for the start of the final stage but soon fell down the order.
Truex Jnr made his way back up to second position by the time there were 60 laps of the scheduled 267 remaining, while Kevin Harvick held top spot.
Harvick and Truex Jnr ran as you were after the final pit stops cycle, albeit much closer together, before the 2017 champion breezed around the outside of the #4 Ford with 20 laps remaining.
Harvick took second, with Brad Keselowski, Chase Elliott, and Ryan Blaney rounding out the top five.
Last year's champion, Joey Logano, was ninth, while the 2019 regular season champion, Kyle Busch ended up 19th having gone a lap down when he scraped the wall.
Truex Jnr's win locks him into the Round of 12, while the Round of 16 continues at Richmond Raceway this coming weekend (September 20-21 local time).
Replay: Kyle Busch hits wall