The Brazilian driver finished the final feature race of the season in P2, which was enough to secure the title after an error from his rival.
Hadjar stalled at the start of the race and was forced to return to the pits, however when he emerged he was already two laps behind the rest of the field.
Gabriel Bortoleto crowned F2 champion
The Frenchman enjoyed an outing in Max Verstappen’s Red Bull during FP1 in Abu Dhabi, but is yet to obtain a full-time F1 drive.
However, Bortoleto will move to Sauber in 2025 where he will race alongside Nico Hulkenberg as the team opt for both youth and experience in their lineup.
“It’s the best feeling in the world. I cannot explain what I am feeling right now,” said Bortoleto.
“It’s just so much adrenaline, so much happiness. Everyone is here to support me – all my family, my sponsors, the whole of Brazil watching us and waking up at six in the morning there. I gave them back happiness on the Sunday morning.
“It’s a dream for me to win F2 in a row after F3, as a rookie. It’s just amazing and I’m not thinking right now. I’m on another planet.”