The 50-minute session also saw Chevrolets sweep the top four positions in single-car runs and eight of the top-10.
Erik Jones led the session most of the way until Kyle Larson jumped to the top with seven minutes remaining and Dillon grabbed the top spot with an average speed of 180.934 mph with two minutes to go.
Alex Bowman ended up second-fastest (180.807 mph), posting his best speed in the final minutes; Larson was third (180.807 mph); Jones ended up fourth (180.318 mph); and Joey Logano fifth (180.096 mph).
Rounding out the top-10 were Daniel Suarez, Tyler Reddick, Ricky Stenhouse Jr., William Byron and Kyle Busch.
There were no on-track incidents during the session.
Kyle Busch (46) completed the most laps.
Larson posted the fastest average lap speed (179.006 mph) among those drivers that ran at least 10 consecutive laps. Byron and Reddick were second and third, respectively.