Driving the No. 54 Joe Gibbs Racing Toyota that he’s taken to wins in both of his Xfinity starts this season, Busch posted a lap at 155.728 miles per hour to lead the session.
JGR teammate Harrison Burton posted the second-fastest lap (154.561 mph).
The session had a single caution for debris.
Xfinity Series qualifying begins Saturday at 12:35 p.m. ET on NBCSN to set the field for the Tennessee Lottery 250 at 3:30 p.m. ET, also on NBCSN.