The 23-year-old Red Bull Racing driver led all 71 laps en route to his fifth Grand Prix victory of the season at the Red Bull Ring for the Austrian GP.
The Tucson, Arizona, native capitalized on teammate Kyle Larson's last-lap misfortune to claim his third victory of 2021 at the Tricky Triangle circuit.
The 26-year-old Ferguson from Lincolnton, North Carolina, will make his second career Truck start with Kaulig Racing more than a month after making his Truck debut at Bristol.
Spire Motorsports has earned one win and three top five finishes. Rajah Caruth took the checkered flag in last year's Rackley Roofing 200 after leading 61 laps.
In 12 previous NASCAR Cup Series starts at Nashville (Tenn.) Superspeedway, Spire Motorsports has two top-five finishes with a best result of second earned twice by Zane Smith (2024) and Carson Hocevar (2025).