Honda’s Marquez made seven attempts across the final three laps to pass Bagnaia, but failed to make a move stick, with the Ducati rider prevailing to become the eighth winner of 2021.
Bagnaia held onto pole position off the line, with Marquez carving past Jack Miller at the first corner to move up to second from fourth on the grid.
An iffy launch for championship leader Quartararo dropped him down to fifth and forward momentum would go wanting for the Yamaha rider over the ensuing laps.
By lap six Quartararo had been shuffled back to seventh by Pramac’s Jorge Martin and Tech 3 KTM rider Iker Lecuona, with the factory KTM of Brad Binder soon finding a way past to demote Quartararo down to ninth.
At the front Bagnaia and Marquez were running a strong pace and quickly put over six tenths between themselves and Miller in third.
And this gap continued to grow over the race as both Bagnaia and Marquez virtually lapped identically in a tense battle for the victory.
Miller’s podium hopes disappeared at the end of lap 11 when he ran off track at the final two corners, allowed Aprilia’s Aleix Espargaro and the Suzuki of Joan Mir to come through.
Mir then moved up to third ahead of Espargaro at the Turn 4 left moments later.
As the race raged on, the gap Bagnaia and Marquez were able to mount to the pack behind swelled above four seconds with 10 of the 23 laps remaining.
A big drop in lap times for the field – all on soft rear rubber – was expected by around lap 15, but Bagnaia and Marquez’s pace remained consistent and strong.
On lap 21 Marquez made his first of seven attempts to take the lead from Bagnaia, this one coming at Turn 5.
But the Honda rider could hold the line through the exit and Bagnaia came straight back through again – doing the exact same thing at Turn 15 later in the lap.
Marquez repeated his attempts at the same two corners on the following tour, but was once again repelled by the Ducati rider.
On the final lap Marquez tried to overtake Bagnaia into the first corner, but ran wide and was repelled again at Turn 5.
Marquez threw one last attempt at Bagnaia into the Turn 12 left, but ran in too hot and left Bagnaia to take the chequered flag 0.673s clear for the Italian to celebrate Ducati’s first Aragon victory since Casey Stoner in 2010.
Reigning world champion Mir completed the podium after Aleix Espargaro dropped off the pace in fourth late on, while Miller rounded out the top five.
Avintia rookie Enea Bastianini carved through to a season-best sixth on his two-year-old Ducati, pipping Binder late on.
Admitting on Saturday that he didn’t feel he had the pace for the podium, Quartararo only just held onto eighth by 0.040s from Martin.
With Bagnaia winning, Quartararo’s championship lead has now been cut from 65 to 53 points heading to Misano.
Takaaki Nakagami completed the top 10 on the sole LCR Honda at the finish after teammate Alex Marquez crashed on lap one, while Lecuona dropped to 11th after a late mistake.
Alex Rins recovered from 20th to 12th on the second Suzuki, with Honda’s Pol Espargaro, Miguel Oliveira on the factory KTM and Tech 3’s Danilo Petrucci securing the final points.
Yamaha stand-in Cal Crutchlow was 16th in what is scheduled to be his last race appearance in 2021, while Johann Zarco plummeted to 17th on his Pramac Ducati having been the only rider to run the medium front tyre.
Maverick Vinales ended his first race as an Aprilia rider in 18th and 27.1s off the victory ahead of Petronas SRT’s Valentino Rossi and Avintia’s Luca Marini.
SRT stand-in Jake Dixon crashed out on the second lap.
Aragon MotoGP - Race results:
|1||> Francesco Bagnaia||>||Ducati|
|2||> Marc Marquez||>||Honda||0.673|
|3||> Joan Mir||>||Suzuki||3.911|
|4||> Aleix Espargaro||>||Aprilia||9.269|
|5||> Jack Miller||>||Ducati||11.928|
|6||> Enea Bastianini||>||Ducati||13.757|
|7||> Brad Binder||>||KTM||14.064|
|8||> Fabio Quartararo||>||Yamaha||16.575|
|9||> Jorge Martin||>||Ducati||16.615|
|10||> Takaaki Nakagami||>||Honda||16.904|
|11||> Iker Lecuona||>||KTM||17.124|
|12||> Alex Rins||>||Suzuki||17.710|
|13||> Pol Espargaro||>||Honda||19.680|
|14||> Miguel Oliveira||>||KTM||22.703|
|15||> Danilo Petrucci||>||KTM||25.723|
|16||> Cal Crutchlow||>||Yamaha||26.413|
|17||> Johann Zarco||>||Ducati||26.620|
|18||> Maverick Viñales||>||Aprilia||27.128|
|19||> Valentino Rossi||>||Yamaha||32.517|
|20||> Luca Marini||>||Ducati||39.073|
|> Jake Dixon||>||Yamaha|
|> Alex Marquez||>||Honda|
|View full results|
Source : https://www.motorsport.com/motogp/news/aragon-bagnaia-ducati-win-marquez-duel/6666211/3564