Marquez's accident came a little over 10 minutes into the 45-minute session, as he tried to avoid his Repsol Honda teammate Dani Pedrosa, who had ran wide just ahead of him at Turn 3.

The two-time champion was clearly in pain after the crash, and it later transpired that the impact had dislocated his shoulder. He had it popped back into place, but didn't reappear for the rest of the session.

UPDATE: Marquez has been transported by helicopter to hospital in the nearby town of Leopen for further inspection on his shoulder.

He will be given a CT scan of the shoulder and collarbone area. It's as yet unknown whether he will take part in qualifying.

Iannone beats Vinales, Lorenzo

Marquez's best time prior to his accident was a 1m24.265s, good enough to put him third overall behind the two works Ducati riders, although that time was bested by Friday pacesetter Andrea Dovizioso on a 1m24.170s.

Maverick Vinales later lowered the bar to a 1m24.007s, which stood as the benchmark until the inevitable late flurry of improvements in the final minutes of the session.

The Suzuki rider became the first man to break into the 1m23s as he posted a 1m23.755s, still a tenth shy of Dovizioso's Friday time, with Jorge Lorenzo slotting in just behind on a 1m23.843s.

But both were blitzed by Andrea Iannone, who hooked up a lap of 1m23.327s - within a tenth of the time he had set in testing last month before the modification was put in place to slow the exit of the final turn.

Vinales and Lorenzo were thus demoted to second and third, ahead of Pramac Ducati man Scott Redding, who launched himself comfortably into the top 10 qualification spots on a 1m23.962s.

Valentino Rossi completed the top five on the second works Yamaha, seven tenths shy of Iannnone, ahead of Aleix Espargaro's Suzuki and Dovizioso, whose Friday time was still enough to put him second overall, behind only his factory Ducati teammate.

Hector Barbera (Avintia Ducati) and the works Hondas of Marquez and Pedrosa completed the top 10 and will therefore proceed directly to Q2.

Missing out on an automatic bye to the second phase of qualifying was LCR Honda man Cal Crutchlow, who crashed out in the closing moments and was powerless to defend his position as he slumped to 12th, one place behind Danilo Petrucci (Pramac Ducati).

Assen winner Jack Miller (Marc VDS) was the only other man to crash, the Australian ending up 19th behind both Tech 3 Yamaha riders.