Vinales and Quartararo ended up over three tenths clear of Honda’s Marc Marquez, who had led most of the session before being surpassed by the Yamahas late on.
Marquez ran in Vinales’ wheeltracks in the opening minutes of the session to log a 1m33.171s, which was just two hundredths off Quartararo’s FP1-topping effort.
The championship leader had run a new soft tyre, and held a nearly half-second lead over nearest rival Vinales until those behind him equipped fresh rubber for the closing runs of FP2.
First, Valentino Rossi closed to within three tenths of Marquez, before the other works Yamaha of Vinales recorded the first sub-1m33s attempt of the weekend.
This 1m32.775s attempt was two tenths quicker than Quartararo’s first push lap on the soft rear tyre, and though the French rookie improved again at the chequered flag, he came up 0.057s short of toppling Vinales.
With the top three made up of the same riders as the morning, Rossi was best of the rest in fourth, albeit seven tenths off the pace.
Quartararo’s Petronas Yamaha teammate Franco Morbidelli made it four Yamahas in the top five, while Pol Espargaro led KTM’s charge in sixth place.
The two factory Ducatis of Danilo Petrucci and Andrea Dovizioso were seventh and eighth respectively, ahead of Suzuki’s Alex Rins and LCR Honda’s Cal Crutchlow.
However, Rins and Crutchlow are currently on course to miss out on automatic spots in Q2, with Aleix Espargaro (Aprilia) and Michele Pirro (Ducati) within the combined classification top 10 instead on the strength of their FP1 laps.
Marquez’s Honda teammate Jorge Lorenzo produced an improved showing compared to the morning, but remains in 17th place – with the top 21 split by 1.6 seconds.