Gresini Ducati rider Alex Marquez took a dominant pole position for MotoGP's Catalan Grand Prix, ahead of a superb Fabio Quartararo.
Championship leader Marc Marquez was only third, struggling for one-lap performance at Barcelona but benefitting from a well-timed tow from his brother.
His Ducati team-mate Pecco Bagnaia's weekend continued in the same vein it had begun on Friday, with the two-time champion never threatening for a Q2 spot during the 15-minute Q1 contest - losing heaps of laptime in the second and fourth sectors.
A last-second improvement at least lifted Bagnaia 0.001s ahead of the still-injured Maverick Vinales, but 21st still marked his second-worst qualifying in MotoGP - better only than the 2022 Portuguese Grand Prix, in which he crashed heavily.
The younger Marquez was already out ahead after the opening runs in Q2, with Marc only sixth - but successfully manoeuvering himself to run behind Alex when the latter set about recording his fastest lap.
That lap ended up a 1m37.536s, putting an end to what had been a close pole fight until then, and Marc lapped four tenths off in his brother's tow, which still proved sufficient for a front row start.
He tried again with his very final attempt but lost the front at Turn 5, saving a crash and aborting the lap.
Tardozzi was like "Calm down, Marc" 🤯@marcmarquez93 produces another incredible save! #CatalanGP 🏁 pic.twitter.com/b8kVR1oKD9
— MotoGP™🏁 (@MotoGP) September 6, 2025
Quartararo will start between them. The Frenchman was already impressive in navigating Q1 with relative ease, then followed Brad Binder to a second-place lap, then did a better lap all on his own in the closing stages.
Binder's KTM team-mate Pedro Acosta, one of the expected pole contenders, had set a lap good enough for third but had it erased for track limits so will start fifth - behind also VR46 Ducati's Franco Morbidelli.
Johann Zarco was the best of the Honda riders in seventh, followed by Ai Ogura (Trackhouse Aprilia) and Enea Bastianini (Tech3 KTM), who both used Acosta as a reference en route to their fastest laps.
Luca Marini (Honda), Binder and Marco Bezzecchi (Aprilia) completed a Q2 covered by 0.825s.
Provisional Catalan GP starting grid
1 A Marquez 2 Quartararo 3 M Marquez
4 Morbidelli 5 Acosta 6 Di Giannantonio
7 Zarco 8 Ogura 9 Bastianini
10 Marini 11 Binder 12 Bezzecchi
13 Aldeguer 14 Miller 15 Fernandez
16 Oliveira 17 Martin 18 Espargaro
19 Rins 20 Mir 21 Bagnaia
22 Vinales 23 Savadori 24 Chantra
Gresini Ducati rookie Fermin Aldeguer was best of the rest in Q1 for 13th on the grid, just 0.004s away from advancing at Di Giannantonio's expense.
Aldeguer will be joined on fifth row by Jack Miller (Pramac Yamaha) and Raul Fernandez (Trackhouse Aprilia).
Joan Mir was fastest on the Honda in pre-qualifying practice, but will have to exploit his race pace from 17th on the grid on Saturday and 20th on Sunday - as a consequence of a three-place grid penalty for impeding Aprilia's Jorge Martin.
