Andrea Iannone remained fastest of all in MotoGP FP2 in a dramatic session at Mugello, with Ducati wildcard rider Michele Pirro suffering a heavy crash as team-mate Andrea Dovizioso was halted by an engine failure.
The session was red-flagged for a first time 15 minutes in after a horror crash for Ducati test rider Pirro, who was thrown over his handlebars after getting unsettled into the braking area of San Donato, the corner at the end of the long pit straight.
The Italian was tended to trackside, where it was confirmed he was conscious, and was taken to the medical centre before being transferred to Florence hospital.
Pirro is reported by his team as having suffered bruising, a dislocated shoulder and remembers nothing of the crash, though was said to have been aware of those around him and has full movement.
Just moments after the session was restarted, a second red flag was flown after the engine in Dovizioso's GP18 expired in spectacular fashion on the run into the first corner.
Dovizioso – who set a record speed of 356.4km/h earlier in the session – was able to rejoin the action on his second bike, but ended up 1.1 seconds off the pace in 12th.
Before the stoppages, Iannone had guided his Suzuki to a 1:47.435s, which he bettered when running got back underway to a 1:47.274s.
Following the first red flag, championship leader Marc Marquez crashed at Materassi on his first flying lap, but was able to get his Honda back to pitlane to be repaired.
With 16 minutes left on the clock, Marquez shot to the top of the timesheets with a 1:47.218s, but was deposed by Yamaha's Maverick Vinales in the closing stages with a 1:47.122s.
Vinales' place at the top of the FP2 standings was short-lived, as Iannone went 0.387s clear of the field with his final effort of 1:46.735s. Marquez completed the top three.
Johann Zarco leapt up the order to fourth in the final minutes on his Tech3 Yamaha with a 1:47.365s, with Pramac's Jack Miller 0.038s further back on his GP17.
Cal Crutchlow headed home hero Valentino Rossi in sixth, while Franco Morbidelli once again shadowed his mentor in eighth. Danilo Petrucci led Ducati stablemate Jorge Lorenzo to round out the top 10.
Dani Pedrosa once again endured a low-key session on the sister factory Honda in 13th, while 16th-placed Aliex Espargaro and 23rd-placed Tom Luthi added their names to the list of San Donato crashers.