The Red Bull junior, who won the sprint race at Silverstone last weekend, took the top spot for Hitech with three minutes left of the session, setting a 1m19.759s.
Other drivers were on course to set their final lap times of the session before Zdanec Chovanec locked up at Turn 1, attempting to avoid the sausage kerb before running wide and coming to a stop, prompting the red flag.
The early ending left many drivers unable to improve, including championship leader Victor Martins (ART), who was forced to settle for second, less than 0.2s behind his compatriot.
Prema Racing’s Ollie Bearman took third, with teammate Arthur Leclerc in fourth, the Silverstone feature race winner having led this morning’s practice session.
Jonny Edgar was first out the pits in his Trident, heading out for qualifying in his second race weekend back after illness.
Martins was first to top the timesheet, setting a 1m19.980s on his maiden attempt as the only driver to break the 1m20s barrier.
Bearman went straight into second, less than 0.1s behind, while Kaylen Frederick was third for Hitech.
The yellow flags were waved briefly 10 minutes into the session after Chovanec stopped right at the pit entry in a bizarre incident for which he will be investigated after the session.
Leclerc moved up from seventh to third on his next attempt, with a 1m20.100s demoting Frederick.
The field dived into the pits, re-emerging with seven minutes left on the clock and causing traffic around the final corner as they jostled for position.
With three minutes remaining, Hadjar snatched the top spot, demoting Martins and Bearman to their final positions before Chovanec’s off ended the session with two minutes left. Moments earlier, ART’s Gregoire Saucy also ran off into the gravel trap.
Frederick took fifth place, with Trident’s Roman Stanek in sixth and Edgar in seventh. Zane Maloney (Trident), Van Amersfoort Racing’s Franco Colapinto and Jak Crawford (Prema) rounded off the top 10.
MP Motorsport’s Caio Collet will start on pole for Saturday’s reverse-grid sprint race, with Juan Manuel Correa in second for ART and Crawford in third.
Bearman faces an investigation for an unsafe release involving Carlin’s Zak O’Sullivan, while David Vidales will be investigated for erratic driving during the final dash to the line.
F3 Austria - Qualifying results:
| Cla | # | Driver | Team | Time | Gap |
|---|---|---|---|---|---|
| 1 | 18 | Isack Hadjar |  HitechGP | 1'19.759 | |
| 2 | 7 |
 Victor Martins | ART Grand Prix | 1'19.980 | 0.221 |
| 3 | 6 | Oliver Bearman |  Prema Powerteam | 1'20.058 | 0.299 |
| 4 | 4 |
 Arthur Leclerc | Prema Powerteam | 1'20.069 | 0.310 |
| 5 | 17 |
 Kaylen Frederick | HitechGP | 1'20.134 | 0.375 |
| 6 | 2 |
 Roman Staněk | Trident | 1'20.178 | 0.419 |
| 7 | 1 |
Jonny Edgar | Trident | 1'20.199 | 0.440 |
| 8 | 3 |
 Zane Maloney | Trident | 1'20.290 | 0.531 |
| 9 | 29 |
 Franco Colapinto |  Van Amersfoort Racing | 1'20.297 | 0.538 |
| 10 | 5 | Jak Crawford | Prema Powerteam | 1'20.351 | 0.592 |
| 11 | 9 |
Juan Manuel Correa | ART Grand Prix | 1'20.380 | 0.621 |
| 12 | 10 |
 Caio Collet | MP Motorsport | 1'20.421 | 0.662 |
| 13 | 23 |
 Ido Cohen |  Jenzer Motorsport | 1'20.431 | 0.672 |
| 14 | 25 |
 William Alatalo | Jenzer Motorsport | 1'20.433 | 0.674 |
| 15 | 26 |
Zak O'Sullivan | Carlin | 1'20.510 | 0.751 |
| 16 | 11 |
 Alexander Smolyar | MP Motorsport | 1'20.516 | 0.757 |
| 17 | 28 |
Enzo Trulli | Carlin | 1'20.568 | 0.809 |
| 18 | 8 |
Gregoire Saucy | ART Grand Prix | 1'20.591 | 0.832 |
| 19 | 20 |
 David Vidales | Campos Racing | 1'20.607 | 0.848 |
| 20 | 22 | Pepe Martí | Campos Racing | 1'20.668 | 0.909 |
| 21 | 31 | Reece Ushijima | Van Amersfoort Racing | 1'20.747 | 0.988 |
| 22 | 19 |
 Nazim Azman | HitechGP | 1'20.782 | 1.023 |
| 23 | 21 | Hunter Yeany | Campos Racing | 1'20.859 | 1.100 |
| 24 | 16 |
Francesco Pizzi | Charouz Racing System | 1'20.868 | 1.109 |
| 25 | 30 |
 Rafael Villagomez | Van Amersfoort Racing | 1'20.927 | 1.168 |
| 26 | 12 |
 Kush Maini | MP Motorsport | 1'21.098 | 1.339 |
| 27 | 27 | Brad Benavides | Carlin | 1'21.304 | 1.545 |
| 28 | 24 |
Federico Malvestiti | Jenzer Motorsport | 1'21.370 | 1.611 |
| 29 | 14 |
 László Tóth | Charouz Racing System | 1'22.566 | 2.807 |
| 30 | 15 | Zdenek Chovanec | Charouz Racing System | 1'27.895 | 8.136 |
| View full results | |||||
