The series veteran, driving for Campos Racing, was untroubled throughout the 23-lap sprint race, leading from the off before cruising home 10 seconds clear of second-placed driver Dennis Hauger.
Boschung had claimed four podiums across the past six seasons in F2, but the top step had evaded him until Saturday's sprint race.
There was a fierce battle for second, with several contenders for runner-up before reigning F3 champion Victor Martins and 2021 F3 champion Hauger (MP Motorsport) were embroiled in a tense tussle in the fading laps.
Hauger, who moved from Prema to MP for his second season in F2, finally claimed second on lap 22, with ART driver Martins settling for third on his debut, having started ninth.
Boschung held firm off the line, with DAMS driver Arthur Leclerc swooping into second and team-mate Ayumu Iwasa taking third.
Iwasa then took second as the pair went side-by-side through the middle sector as Alpine Academy driver Martins moved into fourth around the outside of Turn 11 past Roman Stanek.
A charging Theo Pourchaire, who started 10th, had made it up to fifth by lap three, as Martins took third from Leclerc, both moves up the inside of Turn 1.
Alfa Romeo F1 reserve driver Pourchaire, who finished runner-up last season, then took fourth from Leclerc with the confidence expected of a third-year driver, setting the fastest lap of the race on lap five as he continued his pursuit.
Leclerc was handed a 10-second penalty on lap seven, pitting to serve it and dropping outside the points, while fellow rookie Isack Hadjar (Hitech) did the same.
Martins claimed second from Iwasa up the inside of Turn 1 on lap 13, and despite the Japanese Red Bull junior attempting to reclaim his position, was forced to back off as Pourchaire closed in behind them.
Hauger then repeated Martins' move to pass Pourchaire for fourth place the following lap before setting about passing Iwasa, which he did on lap 15 after a huge lock-up from the DAMS driver.
He bode his time behind Martins before finally securing second on the penultimate lap at Turn 11, relegating Martins to third ahead of Iwasa.
Pourchaire settled for fifth, with MP Motorsport's Jehan Daruvala in sixth and rookie Kush Maini (Campos) in seventh.
Enzo Fittipaldi rounded off the points-paying positions for Rodin Carlin in eighth, with team-mate Zane Maloney in ninth and Juan Manuel Correa (VAR) in 10th.
Series favourite Jack Doohan ran on the alternate strategy, starting on the hard tyre, but failed to break into the top 10.
Leclerc, despite his early promise, finished 12th ahead of Stanek.
| Cla | Driver | Team | Gap |
|---|---|---|---|
| 1 |  Ralph Boschung |
 Campos Racing |
|
| 2 |  Dennis Hauger |
 MP Motorsport |
10.800 |
| 3 |  Victor Martins |
ART Grand Prix |
16.100 |
| 4 |  Ayumu Iwasa |
DAMS |
24.400 |
| 5 | Theo Pourchaire |
ART Grand Prix |
29.700 |
| 6 |  Jehan Daruvala |
MP Motorsport |
30.900 |
| 7 | Kush Maini |
Campos Racing |
41.500 |
| 8 |  Enzo Fittipaldi |
Rodin Carlin | 43.000 |
| 9 |  Zane Maloney |
Rodin Carlin | 44.100 |
| 10 |  Juan Manuel Correa |
Van Amersfoort Racing |
48.500 |
| 11 |  Jack Doohan |
Invicta Virtuosi Racing | 49.200 |
| 12 |  Arthur Leclerc |
DAMS |
50.100 |
| 13 |  Roman Staněk |
 Trident |
50.600 |
| 14 | Jak Crawford |
Hitech Pulse-Eight | 52.200 |
| 15 |  Oliver Bearman |
Prema Powerteam |
53.700 |
| 16 | Clement Novalak |
Trident |
54.600 |
| 17 |  Frederik Vesti |
Prema Powerteam |
54.600 |
| 18 |  Roy Nissany |
PHM Racing by Charouz | 1'04.400 |
| 19 | Brad Benavides |
PHM Racing by Charouz | 1'08.700 |
| 20 | Isack Hadjar |
Hitech Pulse-Eight | 1'13.300 |
| 21 |  Amaury Cordeel |
Invicta Virtuosi Racing | 1'13.800 |
| 22 | Richard Verschoor |
Van Amersfoort Racing |
55.500 |
| View full results | |||
