The dry conditions in FP3 meant improvements on Friday afternoon’s best efforts were immediate, with Quartararo the first bike mover on the combined order as he leaped from 11th to third.
Petronas SRT teammate Franco Morbidelli improved to second, while Valentino Rossi on the works Yamaha moved up to sixth.
With just seven minutes of the session gone, Quartararo had bettered Jack Miller’s 1m34.356s from FP2 with a 1m33.779s and improved to a 1m33.400s a few moments later.
Yamaha took control of the top of the timesheets from this point, with Quartararo going even quicker with a 1m33.301s before Morbidelli edged ahead with a 1m33.279s.
Quartararo once again deposed his teammate with a sequence of session-best laps which culminated in a 1m32.974s.
The Frenchman returned to top spot with 12 minutes to go following another brief spell leading the standings by Morbidelli, with Quartararo lowering the pace to a 1m32.319s as the rest made their final bids for direct passage into Q2.
Quartararo’s lap stood as the benchmark through to the end of the session, while Tech3 KTM’s Miguel Oliveira ended up his nearest challenger 0.130 seconds with a last-gasp effort.
Morbidelli completed the top three ahead of Miller, who suffered a nasty off-throttle highside at the Garage Vert right-hander on an outlap in the closing stages.
Maverick Vinales rounded out the top five on the works Yamaha, with Cal Crutchlow bagging himself a place in Q2 on the LCR Honda in sixth.
A late improvement for Avintia’s Johann Zarco to seventh knocked KTM’s Brad Binder down into 11th, while Rossi was resigned to eighth after crashing at the Dunlop chicane late on.
The Yamaha rider headed Pol Espargaro on the KTM and the factory Ducati of Andrea Dovizioso as the final riders to bag a direct place in Q2.