He returned to his MotoGP race after a 112-day absence following surgery on his broken right arm, and six-time premier class world champion Marquez jumped from 13th on the grid to sixth on the line.
The Honda rider ducked around Quartararo – who started sixth – in Turn 1, but exiting Turn 3, he got a big moment at the rear.
Quartararo was caught unseen and crashed into the back of Marquez, letting the Frenchman who was beaten up by his own Yamaha slide across the tarmac.
Quartararo suffered minor abrasions to his chest and was not seriously injured in the incident.
The incident caused the Yamaha body to become lodged in the rear of Marquez’s bike, which then locked at the rear as he engaged his ride-height device exiting Turn 7.
This led to LCR Honda’s Takaaki Nakagami chasing Marquez in a similar incident to Quartararo’s, with the Japanese rider being eliminated on the spot when Marquez retired from the pit lane at the end of the opening lap.
Bagnaia finished second in a close battle with Bastianini and is now just 10 points behind Quartararo in the standings.
As chaos ensued with Quartararo and Marquez, Bagnaia turned pole into the holeshot for fast-starting Brad Binder on the KTM.
Jack Miller quickly returned to second where he started with a move on Binder at Turn 1 on lap three, with Gresini’s Bastianini passing factory Ducati counterpart Miller at Turn 15 three tours later.
This battle gave Bagnaia a lead of more than seven tenths as he started his seventh tour, although Bastianini had narrowed it to just 0.3 seconds on that lap.
Francesco Bagnaia, Ducati Team
Photo By: Gold and Goose / Motorsport Images
Bastianini used the superior speed of his Gresini-run Ducati GP21 over Bagnaia’s factory GP22 to drag his future teammate into Turn 1 at the start of lap eight.
But the Gresini rider would make a big mistake at Turn 12 one lap later and allow Bagnaia to return to the front of the pack.
The gap between Bagnaia and Bastianini fluctuated between seven tenths and four tenths until the end of lap 19, when the latter came a little closer again.
Despite his Gresini Ducati squirming under the brakes for Turn 12, Bastianini was able to keep Bagnaia in sight and put pressure on him for the next few laps.
But it wouldn’t be until Turn 7 on the final lap that Bastianini found a safe run on Bagnaia to take the lead from him, while the Gresini rider defended his position on the run out of the final two turns with just 0.042 seconds to go. to claim his fourth win of the season.
A lap earlier, Aprilila’s Aleix Espargaro – who sat in fourth for most of the Grand Prix – cleared Binder’s insides to take the last spot on the podium.
With Quartararo’s departure, Espargaro is now just 17 points behind the championship leader, with Bastianini a great chance at 48 points adrift with five races to go in 2022.
Binder held future KTM teammate Miller to four fourths with 0.240s, while Jorge Martin was a distant sixth on his Pramac Ducati ahead of VR46 rider Luca Marini and Johann Zarco on sister Pramac GP22.
Alex Rins went off track at Turn 3 due to the Quartararo/Marquez incident but recovered to ninth on his Suzuki ahead of VR46’s Marco Bezzecchi.
Miguel Oliveira failed to finish 11th on the grid in the race on his KTM, with LCR’s Alex Marquez beating Maverick Vinales’ Aprilia, RNF Racing stand-in Cal Crutchlow and Honda’s Pol Espargaro.
Remy Gardner was 1.2 seconds away from points 16th on his Tech3 KTM ahead of Yamaha’s Franco Morbidelli, RNF’s Darryn Binder, Gresini’s Fabio Di Giannantonio and Tech3’s Raul Fernandez.
Bastianini’s victory has given Ducati the Constructors’ Championship for the third consecutive season.