The Trident rookie, who won the Bahrain feature race, set a 1m33.025s during the final flurry of laps as several drivers crashed in the closing moments of the session.
Bortoleto took an early lead with a 1m34.064s, and despite being demoted by Franco Colapinto, reclaimed the top spot before the end of the session to lead by almost 0.2s.
Second-year ART driver Gregoire Saucy will line up second for Sunday’s feature race, his best-ever series qualifying, ahead of Bahrain polesitter Gabriele Mini (Hitech).
The session was red-flagged shortly after starting, with Pepe Marti crashing while attempting his first flying lap. The Campos Racing driver prompted the first stoppage having cut across the Turns 9 and 10 chicane, sweeping across the gravel and into the barriers.
After a six-minute break, action resumed despite the ominous grey clouds approaching Albert Park.
Bortoleto took an early lead, leading from Luke Browning (Hitech) and ART's Saucy.
Van Amersfoort Racing rookie Tommy Smith almost repeated Marti’s earlier crash at his home race, but escaped by keeping his foot flat, while Nikita Bedrin also had a wobble at Turn 12 in his Jenzer-run car.
As traffic built up, Caio Collet (VAR) moved up five places from 13th to eighth before Franco Colapinto topped the timesheet for MP Motorsport with a 1m33.588s ahead of Prema’s Zak O’Sullivan and Bortoleto, the top nine covered by one second.
Returning to the track with a new set of tyres, Bahrain polesitter Mini took fifth briefly before being demoted by Prema driver Paul Aron and Saucy.
The red flags were waved again moments later after Kaylen Frederick had a huge hit out of the final corner, parking his ART-run car on the main straight.
With just four minutes remaining, the field dashed out for a last attempt at a flying lap, with much jostling for position around the street circuit.
Mini shot to the top of the timesheets before Saucy demoted him, with Bortoleto finally reclaiming the top spot.
Alpine Academy junior Mini then came to a stop on track, having parked up in the Turn 1 gravel, before another crash out of the final corner from Bedrin ended other drivers’ chances of snatching pole.
Trident driver Leonardo Fornaroli will line up fourth, with Prema pair O’Sullivan and Aron in fifth and sixth.
Colapinto starts seventh, with the third Prema of Dino Beganovic ahead of Browning in eighth and ninth.
Sebastian Montoya secured reverse-grid pole for Saturday’s sprint race for Hitech ahead of Trident's Oliver Goethe and Collet.
F3 Australia - Qualifying results
| Cla | Driver | Team | Time | Gap | Interval |
|---|---|---|---|---|---|
| 1 | Gabriel Bortoleto |  Trident |
1'33.025 | ||
| 2 |  Gregoire Saucy |
 ART Grand Prix |
1'33.196 | 0.171 | 0.171 |
| 3 | Gabriele Minì | Hitech Pulse-Eight | 1'33.307 | 0.282 | 0.111 |
| 4 | Leonardo Fornaroli | Trident |
1'33.370 | 0.345 | 0.063 |
| 5 |  Zak O'Sullivan |
Prema Powerteam |
1'33.373 | 0.348 | 0.003 |
| 6 | Paul Aron | Prema Powerteam |
1'33.408 | 0.383 | 0.035 |
| 7 |  Franco Colapinto |
 MP Motorsport |
1'33.588 | 0.563 | 0.180 |
| 8 | Dino Beganovic | Prema Powerteam |
1'33.604 | 0.579 | 0.016 |
| 9 | Luke Browning | Hitech Pulse-Eight | 1'33.765 | 0.740 | 0.161 |
| 10 |  Caio Collet |
Van Amersfoort Racing |
1'33.876 | 0.851 | 0.111 |
| 11 | Oliver Goethe | Trident |
1'34.017 | 0.992 | 0.141 |
| 12 |  Sebastian Montoya |
Hitech Pulse-Eight | 1'34.094 | 1.069 | 0.077 |
| 13 | Christian Mansell |  Campos Racing |
1'34.227 | 1.202 | 0.133 |
| 14 | Jonny Edgar |
MP Motorsport |
1'34.276 | 1.251 | 0.049 |
| 15 | Nikola Tsolov | ART Grand Prix |
1'34.290 | 1.265 | 0.014 |
| 16 | Mari Boya | MP Motorsport |
1'34.326 | 1.301 | 0.036 |
| 17 |  Kaylen Frederick |
ART Grand Prix |
1'34.364 | 1.339 | 0.038 |
| 18 | Taylor Barnard | Jenzer Motorsport |
1'34.394 | 1.369 | 0.030 |
| 19 |  Rafael Villagomez |
Van Amersfoort Racing |
1'34.546 | 1.521 | 0.152 |
| 20 | Nikita Bedrin | Jenzer Motorsport |
1'34.768 | 1.743 | 0.222 |
| 21 | Oliver Gray | Rodin Carlin | 1'35.102 | 2.077 | 0.334 |
| 22 | Hunter Yeany | Rodin Carlin | 1'35.132 | 2.107 | 0.030 |
| 23 | Hugh Barter | Campos Racing |
1'35.133 | 2.108 | 0.001 |
| 24 |  Ido Cohen |
Rodin Carlin | 1'35.359 | 2.334 | 0.226 |
| 25 |  Sophia Flörsch |
PHM Racing by Charouz | 1'35.519 | 2.494 | 0.160 |
| 26 | Roberto Faria | PHM Racing by Charouz | 1'35.688 | 2.663 | 0.169 |
| 27 | Piotr Wiśnicki | PHM Racing by Charouz | 1'36.019 | 2.994 | 0.331 |
| 28 | Tommy Smith | Van Amersfoort Racing |
1'36.314 | 3.289 | 0.295 |
| 29 | Alex Garcia | Jenzer Motorsport |
1'36.596 | 3.571 | 0.282 |
| 30 | Pepe Martí | Campos Racing |
1'56.088 | 23.063 | 19.492 |
| View full results | |||||
