Busch set his top average lap speed of 188.788 mph in the initial 20-minute session but Bubba Wallace came close in the next session with a lap at 188.432 mph.
Denny Hamlin finished up third-fastest, Ty Gibbs was fourth and Martin Truex Jr. rounded out the top-five.
Tyler Reddick was the very best non-Toyota driver used, to arrive sixth overall in his Richard Childress Racing Chevrolet.
The type of drivers who ran finally 10 consecutive laps, Hamlin had the fastest average speed (186.992 mph). Wallace and Gibbs were second and third, respectively, for the reason that category.
Wallace quickly set the pace early in the next 20-minute session then bested it venturing out late and were left with the fastest average lap speed (188.432 mph).
Ty Gibbs, in his third consecutive race completing for Kurt Busch, finished up second-fastest (187.719 mph) and Truex was third (187.436 mph) as Toyota swept the very best three positions.
Tyler Reddick was fourth and Aric Almirola rounded out the top-five.
There have been no on-track incidents through the session.
Kyle Busch was among the first on the right track and set a blistering pace having an average lap speed of 188.788 mph to lead the initial 20-minute session.
Buschs JGR teammate, Hamlin, finished up second-fastest (187.999 mph) and Harvick was third (187.095 mph).
You need to be productive in the way you look at your laps due to the draft. The automobile drives good and well observe how it plays out, Harvick said.
Christopher Bell was fourth and Austin Cindric rounded out the top-five.
There have been no on-track incidents in the initial session.