Francesco Bagnaia posted a late flyer to lead the second Italian MotoGP practice session at Mugello ahead of fellow rookie Fabio Quartararo.
The Pramac Ducati pilot floated around the top 10 during a session that looked set to be dominated once again by Marc Marquez, who had set a time half-a-second quicker than his FP1-leading effort on only his first flying lap.
A flurry of improvements in the final few minutes of the session changed everything, however, as Pol Espargaro initially snatched the top spot thanks to a stunning lap on his KTM RC16.
The Spaniard’s time in the spotlight was shortlived as Danilo Petrucci quickly displaced him, shortly before Quartararo pipped the factory Ducati ace to the fastest time.
Bagnaia’s final effort of 1:46.732 was enough to usurp the Petronas SRT rider for the top spot, with Petrucci pushed down to third as a result.
Pol Espargaro still took the fourth-fastest time, just 0.234 slower than Bagnaia’s benchmark, with Maverick Vinales fifth quickest for the factory Yamaha outfit.
Marquez slipped down to sixth by the end of the session, with Alex Rins Suzuki and Cal Crutchlow's LCR Honda slotting in behind in seventh and eighth places respectively.
Rounding out the top 10 were Jack Miller, who suffered a crash trying to avoid another rider and going into the gravel at Turn 12, and Franco Morbidelli on the second SRT Yamaha machine.
It means a handful of big names will have to improve in FP3 if they are to secure an automatic Q2 spot.
Andrea Dovizioso could only manage 11th quickest on the second factory Ducati, while Johann Zarco was the only other rider to crash during the session in 12th. The Frenchman slipped off his KTM at Turn 11, his RC16 dramatically rolling several times before coming to rest in the gravel trap.
Valentino Rossi and Jorge Lorenzo continued to struggle in the second of Friday’s practice sessions, Rossi managing just the 18th while Lorenzo had to make do with 20th on the timesheets, albeit just 1.3 seconds from the fastest time.
