With the surface of the track bragging with dry stretches of asphalt, premier class riders were testing the mostly metaphorical waters on used rain tyres before fully attacking on slicks. Jack Miller needed no invitation to bravery and went straight to the top of the timesheets on his fresh slick rubber but rivals soon caught up and wanted their share of the limelight. Their wings were quickly clipped by Marc Marquez, who had spent a considerable amount of time in the garage before demolishing the benchmark set by Petrucci a few moments before. The master of changing conditions went unchallenged to the checkered flag, although Johann Zarco did manage to get within half a second of Marquez.
Pol Espargaro continued to impress with a late jump to third and would have enjoyed the company of brother Aleix Espargaro in fourth position. Andrea Dovizioso made some late progress, going from 15th to fifth on his final lap but one full second slower than the leading Honda and half a tenth faster than Maverick Viñales.
Petrucci dropped back to seventh position and ended the session with his Ducati on fire while setting up for a practice start. Hafizh Syahrin seemed to enjoy the conditions and climbed into eighth position, with Takaki Nakagami and Andrea Iannone.
Outside the top ten, Alex Rins was 12 after a late crash that made him miss the final three minutes of action, Jorge Lorenzo fought his way into 16th, Dani Pedrosa took it easy in 19th and Valentino Rossi finished in 22nd. However, with rain on the menu for the whole of Sunday, this session might not prove the most revealing when it comes to the ultimate plotline for the final round battle.