Despite the cool track conditions greeting the riders for the start of FP3, lap time gains were on offer in the first half of the 45-minute session.
Honda’s Pol Espargaro set the early pace on the individual timesheet with a 1m31.908s, before brother Aleix on the Aprilia took over with a 1m31.544s that put him ninth overall.
Having endured a bafflingly off-the-pace day on Friday, Espargaro continued to make progress in FP3 when he moved to sixth on the combined times with a 1m31.405s.
He would improve that again with just over 21 minutes remaining when he found a 1m30.952s to go third overall, while LCR’s Takaaki Nakagami shadowed him by 0.001 seconds in fourth.
With 15 minutes remaining KTM’s Brad Binder became the third rider inside the top 10 to make a combined timesheet improvement in eighth, before Yamaha’s Franco Morbidelli leaped up to fifth with a 1m30.993s – as just 0.068s covered the top six at this stage.
Jack Miller’s Friday best was finally surmounted by 2020 world champion Joan Mir on the Suzuki, who guided his GSX-RR to a 1m30.905s.
This lap was likely to be scrubbed as he passed through a yellow flag zone at Turn 13 after Pol Espargaro suffered a big highside accident, which he needed to be stretchered away from – though was conscious.
He has since been taken to the medical centre for checks.
But Mir followed up this lap with a 1m30.876s when the yellow flag was withdrawn to remain fastest, though only briefly as Miller blitzed him with a 1m30.547s seconds later.
Miller’s lap would continue to stand as the order shuffled dramatically, until Aleix Espargaro found a 1m30.529s to beat the Ducati rider by 0.018s – doing so having just watched the awful accident for his younger brother Pol.
Yamaha’s Morbidelli completed the top three ahead of Bagnaia and the Pramac Ducati of Jorge Martin, with Mir the only Suzuki currently in Q2 after ending FP3 sixth while teammate Alex Rins missed out by 0.041s in 11th.
Rins was denied a direct place in Q2 by Petronas SRT’s Rossi, who used a tow from protege Bagnaia to produce a 1m30.825s to go 10th and just 0.296s off top spot.
He was also just 0.034s behind reigning world champion Fabio Quartararo on the factory Yamaha, with Pramac’s Johann Zarco and Nakagami eighth and seventh.
So tight were the margins in FP3 that just 0.860s covered the entire 21-rider field down to Avintia rookie Enea Bastianini in last.
He will go through Q1 later this afternoon alongside the likes of Rins, KTM duo Brad Binder and Miguel Oliveira, SRT’s Andrea Dovizioso and the sister Aprilia of Maverick Vinales.