Hitech's Deagen Fairclough set the pace as the GB3 Championship made its official on track debut at the Red Bull Ring on Thursday.
The British driver, who took his first win of the year in Race One at the Hungaroring last weekend, set a 1m24.401s in the second session to top the first day of action in Austria.
Fairclough was fastest in two of the three sessions held on the first day, with his session two effort being just over a tenth of a second quicker than his time from session one.
Rodin's Maxim Rehm was just 0.032s behind Fairclough's benchmark, also with a time from session two, while VRD's championship leader Nikita Bedrin was third quickest, with a 1m24.588s, which was the fastest time in the final session.
Elite's Kyuho Lee enjoyed a strong day, setting the fourth quickest time and 0.060s clear of Hillspeed's Dante Vinci who completed the top-five on the combined time sheets.
American contender Oliver Wheldon made his GB3 testing debut with VRD Racing, and was an impressive sixth quickest on his first day in a Tatuus MSV GB3-025 car. The son of double Indy 500-winner Dan Wheldon was 0.047s behind Vinci, courtesy of his session one lap which put him third fastest in his debut session. The USF2000 challenger will return to action tomorrow, but is not entered to race.
Hungaroring pole sitter Martin Molnar put his Rodin Motorsport car seventh thanks to his session two lap, 0.009s behind Wheldon and seven thousandths of a second ahead of Hillspeed's Peter Bouzinelos, who continued his strong form from Hungary on day one at the Red Bull Ring.
Rodin's Abbi Pulling was next up, 0.006s away from Bouzinelos and less than two tenths of a second ahead of the third VRD car of Patricio Gonzalez, which completed the top-10.
Less than a second completed the top-16 drivers on the first day of running, with 1.2s covering the lead-19 contenders. Testing continues tomorrow with three further sessions at 08.30, 13.00 and 17.25 local time.
GB3 Championship, partnered by the BRDC, Red Bull Ring, Thursday practice combined result:
1. Deagen Fairclough, Hitech, 1m24.401s
2. Maxim Rehm, Rodin Motorsport, +0.032s
3. Nikita Bedrin, VRD Racing, +0.187s
4. Kyuho Lee, Elite Motorsport, +0.426s
5. Dante Vinci, Hillspeed, +0.486s
6. Oliver Wheldon, VRD Racing, +0.533s
7. Martin Molnar, Rodin Motorsport, +0.542s
8. Peter Bouzinelos, Hillspeed, +0.549s
9. Abbi Pulling, Rodin Motorsport, +0.555s
10. Patricio Gonzalez, VRD Racing, +0.731s
11. Lucas Fluxa, Xcel Motorsport, +0.796s
12. Jacob Micallef, Hitech, +0.837s
13. Rowan Campbell-Pilling, Xcel Motorsport, +0.857s
14. Aurelia Nobels, Hillspeed, +0.885s
15. Flynn Jackes, Elite Motorsport, +0.916s
16. Leon Wilson, Arden Motorsport, +0.953s
17. Rodrigo Gonzalez, VRD Racing, +1.069s
18. Lewis Gilbert, Arden Motorsport, +1.083s
19. Ricardo Baptista, Xcel Motorsport, +1.202s
20. Yuhao Fu, Hitech, +1.686s