The Yamaha rider now has 69 points, joint with Suzuki’s Alex Rins, who made a stunning charge from 23rd to finish fourth.
Elsewhere, Honda had a difficult weekend, with all their riders struggling for pace.
Marquez led his brother Alex Marquez in sixth, while Espargaro was ninth – all three HRC runners over 16 seconds from the victory.
In the latest Tank Slappers Podcast, Autosport’s Lewis Duncan and Motorsport.com’s Oriol Puigdemont discuss how Quartararo has made the Yamaha work to his advantage and what he’s doing differently to the outfit’s other riders.
They also mull over what’s going on at Honda and why Rins could be in the title fight this year.