Bastianini, a three-time winner in the premier class, snatched pole from Ducati's Francesco Bagnaia on the final lap, finishing 0.024 seconds ahead of him. Bagnaia's team Jack Miller came third as Ducati completed a front row lockout.
Pramac Ducati's Jorge Martin finished fourth and Johann Zarco came sixth as world championship leader Fabio Quartararo had to settle for the fifth spot on his Yamaha.
"It had been a long time for me without a pole position," said Italian Bastianini, who made his premier class debut at Qatar in 2021.
"Today we arrived prepared for the qualifying and at the end I am very happy, also for Gresini and Ducati, we are on top for tomorrow.
"It will be a ready hard race because Fabio is really fast here, but I want to arrive tomorrow and battle with this guy."
