The Van Amersfoort Racing rookie, who took pole for the feature race in Bahrain, claimed his maiden series win after a much-interrupted race.
Having started on pole in the reverse-grid sprint, he lost the lead to Caio Collet on lap 4 after the MP Motorsport driver took advantage of DRS on the main straight.
Colapinto held on to second place throughout, before he was able to regain the lead from Collet after the virtual safety car ended on the final tour.
Seconds later, Collet’s race was dramatically ended after he made contact with Isack Hadjar, who was attempting to pass him on the run down to Tamburello.
The crash promoted Victor Martins to second, having been running in fourth for ART Grand Prix, with Prema Racing’s Jak Crawford taking his second series podium in third.
Colapinto had a good start off the line, with second-place starter Ido Cohen getting swallowed up by Kush Maini and Collet on the run down to Turn 1.
Hadjar took fourth from Martins at Tamburello on Lap 4, before passing Maini for third at the Villeneuve chicane three laps later.
The first safety car was deployed on lap 9 after Zak O’Sullivan went off at Turn 6, shortly followed by Pepe Marti in a separate incident.
Racing resumed on lap 11, with Maini taking a drive-through penalty for being outside his grid box at the start and dropping him out of podium contention, promoting Crawford to fifth place.
The safety car was promptly deployed for a second time after Reece Ushijima and Federico Malvestiti collided at Tamburello, with the Van Amersfoort driver collecting the Jenzer driver, making his debut, as he went off.
Cohen was also forced to pit for a new front wing after making contact with Kaylen Frederick on the restart.
The lights went green again on lap 17, with Collet holding onto the lead from Colapinto, before Arthur Leclerc wiped out the 150-metre board at the exit of Villeneuve, prompting a virtual safety car.
A tussle for fourth ensued on the restart, with Crawford and Martins battling for fourth.
It was on the final lap where the decisive crash took place, with Colapinto snatching the lead before Hadjar ran into the rear of a second-place running Collet, ending the Brazilian’s race and running across the gravel to emerge in fifth.
Roman Stanek took advantage of the incident to take fourth place for Trident, with rookie teammate Zane Maloney in sixth.
Oliver Rasmussen finished seventh in his first race of the season having replaced Jonny Edgar at Trident, while Frederick managed to emerge from the collision with Cohen unscathed to take eighth.
Ollie Bearman, who suffered several offs and looked like he had a mechanical issue at one point during the sprint, made it to 13th, while teammate Leclerc, who started in 21st but was running as high as 12th at one point after a charge through the field, finished 14th.
