Colapinto took control of the race after executing a brilliant pass on poleman Sebastian Montoya through the Turns 9/10 complex after the first of three safety car restarts.
The MP Motorsport driver then survived two subsequent restarts and was over three seconds clear of the field when the safety car was called for the fourth and final time, with the first-ever F3 race at Albert Park ending under caution.
Prema’s Zak O’Sullivan made it a one-two for Williams-affiliated drivers after going around the outside of Hitech man Montoya in the closing stages.
Reverse grid polesitter Montoya initially held the advantage at the start as Oliver Goethe and Luke Browning tussled over second heading through Turns 1 and 2.
Browning looked to have cleared Goethe when the two cars made light contact on the run down to Turn 3, giving the latter driver a puncture and ploughing into the gravel and prompting the first safety car of the race.
Montoya led Browning and Colapinto - up from sixth on the grid - at the restart, with Browning immediately putting his Hitech team-mate Montoya under pressure.
But the Autosport BRDC Young Driver Award Winner lost ground on lap 5 of 20 when he went over the kerbs at Turn 9, briefly sending the nose of his Hitech-run machine skywards, allowing Colapinto to take over as Montoya’s nearest challenger.
The following lap, Colapinto pulled off the move that Browning couldn’t to take a lead he wouldn’t lose, moments before the safety car was called a second time to retrieve the stricken Rodin Carlin car of Ido Cohen.
Colapinto quickly gapped Montoya at the subsequent restart, with O’Sullivan, by now up to third from eighth on the grid, now challenging for second.
But the British driver would have to wait until lap 18, following another caution triggered by local driver Tommy Smith hitting the barriers at the final corner, before finally getting an opportunity to pass Montoya around the outside at Turns 11 and 12.
Montoya hung on for the final podium spot, marking his first top-three finish in F3.
Paul Aron survived contact with Caio Collet to grab fourth for Prema, albeit with that incident to be investigated after the race, while Alpine junior Gabriele Mini grabbed fifth from Dino Beganovic in the latter stages when Aron pushed his Prema team-mate wide at Turn 3.
Points leader and feature race polesitter Gabriele Bortoleto claimed seventh ahead of Leonardo Fornaroli, Mari Boya and Gregoire Saucy.
Browning finally finished 11th on the road with what he believed was a damaged car, but was relegated to 20th by a 10-second penalty for causing a collision.
F3 Australia - sprint race results (20 laps):
| Cla | Driver | Team | Laps | Time |
|---|---|---|---|---|
| 1 |  Franco Colapinto |
 MP Motorsport |
20 | - |
| 2 |  Zak O'Sullivan |
 Prema Powerteam |
20 | 0.4 |
| 3 |  Sebastian Montoya |
Hitech Pulse-Eight | 20 | 0.7 |
| 4 | Paul Aron | Prema Powerteam |
20 | 1.0 |
| 5 | Gabriele Minì | Hitech Pulse-Eight | 20 | 1.2 |
| 6 | Dino Beganovic | Prema Powerteam |
20 | 1.8 |
| 7 | Gabriel Bortoleto | Trident |
20 | 2.0 |
| 8 | Leonardo Fornaroli | Trident |
20 | 2.4 |
| 9 | Mari Boya | MP Motorsport |
20 | 3.4 |
| 10 |  Gregoire Saucy |
 ART Grand Prix |
20 | 3.9 |
| 11 | Jonny Edgar |
MP Motorsport |
20 | 6.0 |
| 12 | Christian Mansell |  Campos Racing |
20 | 7.8 |
| 13 |  Kaylen Frederick |
ART Grand Prix |
20 | 8.8 |
| 14 | Nikola Tsolov | ART Grand Prix |
20 | 9.3 |
| 15 | Taylor Barnard | Jenzer Motorsport |
20 | 10.3 |
| 16 | Pepe Martí | Campos Racing |
20 | 11.4 |
| 17 |  Rafael Villagomez |
Van Amersfoort Racing |
20 | 13.5 |
| 18 | Nikita Bedrin | Jenzer Motorsport |
20 | 13.6 |
| 19 |  Sophia Flörsch |
PHM Racing by Charouz | 20 | 14.1 |
| 20 | Luke Browning | Hitech Pulse-Eight | 20 | 15.1 |
| 21 | Roberto Faria | PHM Racing by Charouz | 20 | 16.2 |
| 22 | Hugh Barter | Campos Racing |
20 | 16.8 |
| 23 | Oliver Gray | Rodin Carlin | 20 | 18.1 |
| 24 |  Caio Collet |
Van Amersfoort Racing |
20 | 19.2 |
| 25 | Hunter Yeany | Rodin Carlin | 20 | 20.4 |
| 26 | Piotr Wiśnicki | PHM Racing by Charouz | 20 | 21.0 |
| Alex Garcia | Jenzer Motorsport |
17 | 3 laps | |
| Tommy Smith | Van Amersfoort Racing |
12 | 8 laps | |
 Ido Cohen |
Rodin Carlin | 5 | 15 laps | |
| Oliver Goethe | Trident |
0 | ||
| View full results | ||||
