GP3 Series leader Alex Lynn was in imperious form in free practice at the Red Bull Ring on Friday evening.
The Red Bull junior set a sequence of blisteringly-quick laptimes to top the 45-minute session by over half a second.
After an early challenge from ART's Dino Zamparelli, Lynn traded the top spot with his Carlin team-mate Emil Bernstorff.
They swapped the fastest time four times, before Lynn's pace became untouchable, and he ended the session on a 1m20.538s.
Bernstorff had to settle for second, 0.587 seconds slower and 0.007s ahead of Nick Yelloly of Status.
Koiranen's Santiago Urrutia rocketed up to fourth in the closing seconds, ahead of Hilmer's newcomer Riccardo Agostini and his team-mate Nelson Mason.
Ritchie Stanaway, who had been near the top of the times early on, slumped back to 16th. The other Barcelona race winner Dean Stoneman was 12th.
The session was temporarily halted after Trident's Roman de Beer spun into the pitwall after going off at the final corner. He was unhurt.
Pos Driver Team Time Gap
1. Alex Lynn Carlin 1m20.538s
2. Emil Bernstorff Carlin 1m21.125s +0.587s
3. Nick Yelloly Status 1m21.132s +0.594s
4. Santiago Urrutia Koiranen 1m21.287s +0.749s
5. Riccardo Agostini Hilmer 1m21.351s +0.813s
6. Nelson Mason Hilmer 1m21.371s +0.833s
7. Patrick Kujala Manor 1m21.390s +0.852s
8. Robert Visoiu Arden 1m21.411s +0.873s
9. Alfonso Celis Jr Status 1m21.460s +0.922s
10. Dino Zamparelli ART 1m21.473s +0.935s
11. Matheo Tuscher Jenzer 1m21.481s +0.943s
12. Dean Stoneman Manor 1m21.497s +0.959s
13. Marvin Kirchhofer ART 1m21.548s +1.010s
14. Patric Niederhauser Arden 1m21.658s +1.120s
15. Jann Mardenborough Arden 1m21.905s +1.367s
16. Richie Stanaway Status 1m21.952s +1.414s
17. Alex Fontana ART 1m21.953s +1.415s
18. Luis Sa Silva Carlin 1m22.026s +1.488s
19. Pal Varhaug Jenzer 1m22.269s +1.731s
20. Adderly Fong Jenzer 1m22.295s +1.757s
21. Jimmy Eriksson Koiranen 1m23.021s +2.483s
22. Nikolay Martsenko Hilmer 1m23.403s +2.865s
23. Ryan Cullen Manor 1m23.656s +3.118s
24. Roman de Beer Trident 1m23.902s +3.364s
25. Victor Carbone Trident 1m24.462s +3.924s
26. Carmen Jorda Koiranen 1m24.687s +4.149s